Avaya Configuring Data Compression Services User's Manual
Contents
1. Bay Networks uses the draft RFC Compression Control Protocol CCP only to enable or disable compression for PPP CCP also includes a history reset request and acknowledgment capability but our implementation of data compression does not use these features Bay Networks Compression WCP Bay Networks data compression uses WAN Compression Protocol WCP which is an IETF draft standard WCP enables compression for Frame Relay and for X 25 and transports compressed packets for Frame Relay X 25 and PPP WCP negotiates compression mode history size and buffer size For Frame Relay and PPP WCP also retransmits packets in the event of packet loss and protects against inadvertent data expansion LAPB retransmits packets for X 25 2 2 117352 A Rev A Data Compression Overview Data Compression Performance The goals in using data compression are to achieve a high compression ratio while maximizing throughput Compression ratio is the size of uncompressed data compared to the size of the same data after it has been compressed Throughput refers to the speed of transmitting data The compression ratio varies according to the effectiveness of the compression algorithm but also according to the characteristics of the data you are transmitting data that includes a lot of redundant strings compresses at a high ratio Throughput or network response time varies with the number of elements in the network that the data must traverse2. Configuring Data Compression Services BayRS Version 12 00 Site Manager Software Version 6 00 Part No 117352 A Rev A September 1997 rS Bay Networks Bay Networks 4401 Great America Parkway 8 Federal Street Santa Clara CA 95054 Billerica MA 01821 Copyright 1997 Bay Networks Inc All rights reserved Printed in the USA September 1997 The information in this document is subject to change without notice The statements configurations technical data and recommendations in this document are believed to be accurate and reliable but are presented without express or implied warranty Users must take full responsibility for their applications of any products specified in this document The information in this document is proprietary to Bay Networks Inc The software described in this document is furnished under a license agreement and may only be used in accordance with the terms of that license A summary of the Software License is included in this document Trademarks ACE AFN AN BCN BLN BN BNX CN FN FRE GAME LN Optivity PPX Bay Networks SynOptics SynOptics Communications Wellfleet and the Wellfleet logo are registered trademarks and Advanced Remote Node ANH ARN ASN BaysSIS BayStack BayStream BCNX BLNX EZ Install EZ Internetwork EZ LAN IP AutoLearn PathMan PhonePlus Quick2Config RouterMan SN SPEX Switch Node Bay Networks Press the Bay Networks logo and the SynOptics logo are trademarks
3. grants the end user of the Software Licensee a personal nonexclusive nontransferable license a to use the Software either on a single computer or if applicable on a single authorized device identified by host ID for which it was originally acquired b to copy the Software solely for backup purposes in support of authorized use of the Software and c to use and copy the associated user manual solely in support of authorized use of the Software by Licensee This license applies to the Software only and does not extend to Bay Networks Agent software or other Bay Networks software products Bay Networks Agent software or other Bay Networks software products are licensed for use under the terms of the applicable Bay Networks Inc Software License Agreement that accompanies such software and upon payment by the end user of the applicable license fees for such software 2 Restrictions on use reservation of rights The Software and user manuals are protected under copyright laws Bay Networks and or its licensors retain all title and ownership in both the Software and user manuals including any revisions made by Bay Networks or its licensors The copyright notice must be reproduced and included with any copy of any portion of the Software or user manuals Licensee may not modify translate decompile disassemble use for any competitive analysis reverse engineer distribute or create derivative works from the Software or user manuals or any
4. Compression Mode parameter page A 2 line page A 6 circuit interface Maximizing Throughput Each side of the link has both a compression and decompression history and a lookup table The compression and decompression histories maintain a record of data that has already traveled across the network The lookup tables maintain pointers to redundant strings and the offset and length tokens that replace each of those strings You can specify either 8 KB or 32 KB of local memory to maintain a compression history If the link uses software compression with a history of 8 KB each end of the link allocates 8 KB of memory for compression 16 KB for the compression lookup table and 8 KB for decompression or 32 KB If the link uses a compression history of 32 KB each end of the link allocates 32 KB of memory for compression 64 KB for the compression lookup table and 32 KB for decompression for a total of 128 KB Hardware compression entails similar requirements If you select different values for history size for the two sides of the link 8 KB becomes the history size for both sides of the link 8 KB History Size In general 8 KB histories are appropriate for Frame Relay and X 25 when you have large numbers of VCs and need to be conservative when you allocate memory to each of them 32 KB History Size For PPP with only one circuit per line you may want to use a 32 KB history You may want to allocate a 32 KB history size fo
5. Interfaces Inherit from Line 32 K 8K Inherit from Line Indicates the amount of memory allocated to compression history for the circuit Remember that history size entails separate compression and decompression histories and lookup tables on each side of a link For example if the link uses software compression with a history of 8 KB each end of the link allocates 8 KB of memory for compression 16 KB for a compression lookup table and 8 KB for decompression or 32 KB total If the link uses a compression history of 32 KB each end of the link allocates 32 KB of memory for compression 64 KB for a compression lookup table and 32 KB for decompression for a total of 128 KB Hardware compression entails similar requirements Selecting 32 K for PPP WCP should not pose a problem for the BN because PPP allows only one circuit per line Select 8 K or 32 K for Frame Relay and X 25 lines depending on the resources of your network Selecting 32 K for PPP WCP on the ASN can cause problems particularly if you are using a 32 context compression net module In general 8 KB histories are appropriate for WAN links that run at 64 Kb s or less because less throughput is required Use an 8 KB history size with Frame Relay and X 25 which have large numbers of VCs and low available bandwidth and with PPP on a 32 context net module You may want to allocate a 32 KB history size for links with speeds higher than 64 Kb s to improve throughput The co
6. 3 6 1 4 1 18 3 4 22 1 1 2 117352 A Rev A A 1 Configuring Data Compression Services Parameter Path Default Options Function Instructions MIB Object ID Compression Mode Configuration Manager Protocols WCP Lines Continuous Packet Continuous Packet Packet by Packet Continuous Packet Compression CPC retains compression history across packets and allows a higher compression ratio than does Packet by Packet Compression PPC PPC resets compression history at the start of each packet resulting in a lower compression ratio Since PPC does not depend on previous packets you should select this option for a link that drops a large number of packets Select either Continuous Packet or Packet by Packet 1 3 6 1 4 1 18 3 4 22 1 1 5 A 2 117352 A Rev A Parameter Path Default Options Function Instructions MIB Object ID Data Compression Parameters History Size Configuration Manager Protocols WCP Lines 32K 32Kl8K Indicates the amount of memory allocated to compression history for the line Remember that history size entails separate compression and decompression histories and lookup tables on each side of a link For example if the link uses software compression with a history of 8 KB each end of the link allocates 8 KB of memory for compression 16 KB for a compression lookup table and 8 KB for decompression or 32 KB total If the link uses a compression history of
7. 32 KB each end of the link allocates 32 KB of memory for compression 64 KB for a compression lookup table and 32 KB for decompression for a total of 128 KB Hardware compression entails similar requirements Selecting 32 K for PPP WCP should not pose a problem for the BN because PPP allows only one circuit per line Select 8 K or 32 K for Frame Relay and X 25 lines depending on the resources of your network Selecting 32 K for PPP WCP on the ASN can cause problems particularly if you are using a 32 context compression net module In general 8 KB histories are appropriate for WAN links that run at 64 Kb s or less because less throughput is required Use an 8 KB history size with Frame Relay and X 25 which have large numbers of VCs and low available bandwidth and with PPP on a 32 context net module You may want to allocate a 32 KB history size for links with speeds higher than 64 Kb s to improve throughput The compression engine can find a data pattern match up to three times faster using a 32 KB history than an 8 KB history If you select different history sizes for the two sides of a link the smaller of the two becomes the effective history size Select either 32 K or 8 K 1 3 6 1 4 1 18 3 4 22 1 1 6 117352 A Rev A A 3 Configuring Data Compression Services Parameter Path Default Options Function Instructions MIB Object ID Buffer Size Configuration Manager Protocols WCP Lines Normal
8. always able to add an 8 KB context because 8 KB is the smallest divisible amount of compression memory Site Manager History Size parameter page A 3 line page A 7 circuit interface Preventing Data Loss for Frame Relay and PPP Buffer size is the amount of memory allocated to keep the transmission history You must configure this parameter to protect against data loss if you run Frame Relay or PPP You can use a buffer size of None Normal Large or Very Large The default value is Normal Configure buffer space based on the following conditions Length of time it takes for data to travel over the link A Normal buffer size usually suffices for a coast to coast connection within the United States You may need a Large or Very Large buffer if your link is over a satellite connection Number of dropped packets Increase the buffer size on a link with a large number of dropped packets Decrease the buffer size even to None to conserve memory on a link with a very small number of dropped packets 3 4 117352 A Rev A Customizing Data Compression e Number of resets Increase the buffer size for a link with a large number of resets and a low number of dropped packets Be aware however that a high number of resets may occur for reasons unrelated to buffer size Note X 25 is a reliable protocol which means that it has features that check for errors and prevent data loss Bay Networks data compres
9. dial backup 2 10 dial on demand 2 10 multiline 2 9 multilink 2 10 preventing data loss for Frame Relay and PPP 3 4 publications ordering xv S software compression 2 3 configuring 1 1 starting data compression 1 1 to 1 3 Index 2 1 Technical Solutions Centers xvi throughput 2 3 3 2 W WCP definition 2 2 deleting from a router 1 4 features 2 12 initialization 2 6 negotiations 2 7 overview 2 1 to 2 12 World Wide Web page Bay Networks xvii X X 25 data compression features 2 11 DDN service 2 11 Max Window Size parameter 2 11 PDN service 2 11 117352 A Rev A
10. establishes a backup line You cannot enable any protocols including compression on a backup circuit because a backup circuit inherits its protocols from the primary circuit If the primary circuit uses compression then the backup circuit does also For further information on Bay Networks dial services refer to Configuring Dial Services 2 10 117352 A Rev A Data Compression Overview X 25 Services An X 25 network permits as many as 128 VCs to exist on the same physical link at the same time You can configure each of those interfaces individually to use data compression or not X 25 PDN and DDN Services When you use data compression on circuits that you configure for X 25 PDN or DDN services you must be careful to enable compression on both sides of the link If you configure compression on only one side of a PDN or DDN link the data that travels over that link will be garbled You must also remember to enable the X 25 service record compression parameter for each X 25 interface that you configure See Configuring X 25 Services for more information about this parameter Adjusting X 25 Max Window Size Window size can affect packet throughput across the X 25 network Setting the X 25 Max Window Size parameter too low can cause the router to drop packets and render data compression ineffective You should configure this parameter at a higher value than the default setting Summary of Bay Networks Data Compression Featu
11. including the compression decompression process Software Compression Hardware Bay Networks software based data compression is most effective for sites that have WAN connections at relatively low speeds such as 56 64 KB where you want to achieve data compression at low cost and with minimal memory requirements It supports up to 512 Kb s on the FRE 040 For networks operating at faster speeds you should use hardware compression Compression Bay Networks hardware based compression works with Frame Relay and PPP networks It best serves sites that support T 1 E 1 lines which often concentrate many lower speed remote connections Our hardware compression facility operates at high speeds and also supports high density WAN connections Use hardware compression when you want to achieve high compression ratios and throughput and also want to preserve router memory to perform other functions We offer two compression daughterboards for the BN and two compression net modules for the ASN 117352 A Rev A 2 3 Configuring Data Compression Services Hardware Compression for the BN The compression daughterboards for the BN are e AG2104037 Octal Sync with a 32 contexts hardware compression daughterboard e AG2104038 Octal Sync with a 128 contexts hardware compression daughterboard Hardware Compression for the ASN The hardware compression net modules for the ASN can compress data transmitted over WAN networks attached t
12. of Bay Networks Inc All other trademarks and registered trademarks are the property of their respective owners Restricted Rights Legend Use duplication or disclosure by the United States Government is subject to restrictions as set forth in subparagraph c 1 ii of the Rights in Technical Data and Computer Software clause at DFARS 252 227 7013 Notwithstanding any other license agreement that may pertain to or accompany the delivery of this computer software the rights of the United States Government regarding its use reproduction and disclosure are as set forth in the Commercial Computer Software Restricted Rights clause at FAR 52 227 19 Statement of Conditions In the interest of improving internal design operational function and or reliability Bay Networks Inc reserves the right to make changes to the products described in this document without notice Bay Networks Inc does not assume any liability that may occur due to the use or application of the product s or circuit layout s described herein Portions of the code in this software product are Copyright 1988 Regents of the University of California All rights reserved Redistribution and use in source and binary forms of such portions are permitted provided that the above copyright notice and this paragraph are duplicated in all such forms and that any documentation advertising materials and other materials related to such distribution and use acknowledge that
13. ssssssss uL Staring Data Compression ar 4 25 EE 1 8 Finding CS a p ld D E 1 3 Deleting Data Compression rom a Platon ae anaes 1 4 Chapter 2 Data Compression Overview Data Compression Architecture EEE NR ne a 2 2 L277 AB aaa 2 2 Compression Control Protocol GGP aussen 2 2 Bay N iworks Compression DP EE 2 2 Data Compression ege 2 8 Software Compression UR EO ce 2 3 117352 A Rev A V Fapdware Complies ciai ae nt 2 3 Hardware Compression for the BN EE 2 4 Hardware Compression for the ASN anne a cea ani 2 4 Hardware Compression Lane asus 2 4 How Data Compression Works ee TUE che 2 5 DEP ille een 2 7 IP NEST AND een nenne 2 7 Data Transmission TT Tm Tm T 2 1 Compression Features for Specific Protocols AAA 2 8 Sech 2 8 Frame Rey Hybrid ACCESS anne 2 8 Famo Raby Dial e E 2 8 Frame Relay Multiline Seales NEE n EE 2 9 duc i c 2 9 PEP TOREM k 2 9 PPP MORIK zeigen TUE TUE EE 2 10 PPEBandwidui ar E TE 2 10 PPF DORN DENAN cp pa 2 10 PPF DOLER RUD nee 2 10 PACCO Rec no 2 11 A 25 PON and DON Services nn m Reeg 2 11 Adusing X25 EA TE 2 11 Summary of Bay Networks Data Compression Features ussssesnnnnennesennnnennennnnn nn 2 11 Software Based Data Compression REN Wa een See Vereen 2 12 Hardware Based Data Compression u 2 12 Chapter 3 Customizing Data Compression Pid seins Compression Memar ARR M 3 1 ob
14. 352 A Rev A About This Guide For More Information For information about Bay Networks and its products visit the Bay Networks World Wide Web WWW site at http www baynetworks com To learn more about Bay Networks Customer Service select Customer Service on the opening Web page 117352 A Rev A xvii Chapter 1 Starting Compression The quickest way to begin using data compression on your network is to enable it with the default values that Bay Networks software supplies The procedures in this chapter describe how Preparing a Configuration File Before you can start data compression you must 1 Create and save a configuration file that has at least one WAN interface 2 Retrieve the configuration file in local remote or dynamic mode 3 Specify router hardware if this is a local mode configuration file Configuring Software Compression Software compression works on all router platforms and all serial interfaces You can use software compression with Frame Relay PPP or X 25 To configure software compression 1 Select the link or net module connector on which you are enabling data compression 2 Specify Frame Relay PPP or X 25 as the WAN protocol Site Manager Path From the Protocols window that appears after you select the link or net module select PPP Frame Relay or X 25 Click on OK The Select Protocols window appears 117352 A Rev A 14 Configuring Data Compression Services Fo
15. Agreement contact Bay Networks Inc 4401 Great America Parkway P O Box 58185 Santa Clara California 95054 8185 LICENSEE ACKNOWLEDGES THAT LICENSEE HAS READ THIS AGREEMENT UNDERSTANDS IT AND AGREES TO BE BOUND BY ITS TERMS AND CONDITIONS LICENSEE FURTHER AGREES THAT THIS AGREEMENT IS THE ENTIRE AND EXCLUSIVE AGREEMENT BETWEEN BAY NETWORKS AND LICENSEE WHICH SUPERSEDES ALL PRIOR ORAL AND WRITTEN AGREEMENTS AND COMMUNICATIONS BETWEEN THE PARTIES PERTAINING TO THE SUBJECT MATTER OF THIS AGREEMENT NO DIFFERENT OR ADDITIONAL TERMS WILL BE ENFORCEABLE AGAINST BAY NETWORKS UNLESS BAY NETWORKS GIVES ITS EXPRESS WRITTEN CONSENT INCLUDING AN EXPRESS WAIVER OF THE TERMS OF THIS AGREEMENT 117352 A Rev A Contents About This Guide Bas VOU EE D xiii Conventions Tl TEES xiv DENE Eesen pr tennant aaa soa ea epe s Duc ar S copa sat cain ae XV Ordering Bay Networks Publiestions seen ren XV Bay Neiworks Customer Sa e esas na ee xvi FO E a E ask xvi ade A ngu e rt n We xvii Chapter 1 Starting Compression mi d ypespte nez E 1 1 Contiguring Sofbware Compressi n anne 1 1 Configuring Hardware Gompression i e eti pred snoin t He tex RP RE ER CURA 1 2 Configuring Compression for the Backbone Node BN sssss 1 2 Configuring Compression for the Access Stack Node ASN 1 2 SAEI Daa COOPER SIBEL nennen 1 3 Starting Data Compression for Frame Relay and PPP
16. Rev A XV Configuring Data Compression Services Bay Networks Customer Service You can purchase a support contract from your Bay Networks distributor or authorized reseller or directly from Bay Networks Services For information about or to purchase a Bay Networks service contract either call your local Bay Networks field sales office or one of the following numbers Region Telephone number Fax number United States and 1 800 2LANWAN then enter Express Canada Routing Code ERC 290 when prompted to purchase or renew a service contract 1 508 916 8880 direct 1 508 916 3514 Europe 33 4 92 96 69 66 33 4 92 96 69 96 Asia Pacific 61 2 9927 8888 61 2 9927 8899 Latin America 561 988 7661 561 988 7550 How to Get Help If you purchased a service contract for your Bay Networks product from a distributor or authorized reseller contact the technical support staff for that distributor or reseller for assistance If you purchased a Bay Networks service program call one of the following Bay Networks Technical Solutions Centers Technical Solutions Center Telephone number Fax number Billerica MA 1 800 2LANWAN 508 916 3514 Santa Clara CA 1 800 2LANWAN 408 495 1188 Valbonne France 33 4 92 96 69 68 33 4 92 96 69 98 Sydney Australia 61 2 9927 8800 61 2 9927 881 1 Tokyo Japan 81 3 5402 0180 81 3 5402 0173 xvi 117
17. S OR IMPLIED INCLUDING WITHOUT LIMITATION ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE Licensee is responsible for the security of 117352 A Rev A iii its own data and information and for maintaining adequate procedures apart from the Software to reconstruct lost or altered files data or programs 4 Limitation of liability IN NO EVENT WILL BAY NETWORKS OR ITS LICENSORS BE LIABLE FOR ANY COST OF SUBSTITUTE PROCUREMENT SPECIAL INDIRECT INCIDENTAL OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES RESULTING FROM INACCURATE OR LOST DATA OR LOSS OF USE OR PROFITS ARISING OUT OF OR IN CONNECTION WITH THE PERFORMANCE OF THE SOFTWARE EVEN IF BAY NETWORKS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES IN NO EVENT SHALL THE LIABILITY OF BAY NETWORKS RELATING TO THE SOFTWARE OR THIS AGREEMENT EXCEED THE PRICE PAID TO BAY NETWORKS FOR THE SOFTWARE LICENSE 5 Government Licensees This provision applies to all Software and documentation acquired directly or indirectly by or on behalf of the United States Government The Software and documentation are commercial products licensed on the open market at market prices and were developed entirely at private expense and without the use of any U S Government funds The license to the U S Government is granted only with restricted rights and use duplication or disclosure by the U S Government is subject to the restrictions set forth in subparagraph c 1 of the Commercial Compute
18. Very Large Large Normal None Indicates the amount of buffer memory for the transmission history on a line Set this parameter according to the end to end round trip length of a WCP connection Select Normal for most land line coast to coast connections Select Large or Very Large for connections at a great distance from each other such as satellite connections Select None for links that drop a very small number of packets Increase the buffer size for a link with a large number of resets 1 3 6 1 4 1 18 3 4 22 1 1 7 Note Because X 25 has features that check for errors and prevent data loss Bay Networks data compression software ignores the Buffer Size parameter for X 25 If you are configuring compression for X 25 you do not have to set this parameter Parameter Path Default Options Function Instructions MIB Object ID Engine Type Configuration Manager gt Protocols gt WCP gt Lines Software unless you have configured either an Octal Sync Link module that has a hardware compression daughterboard for the BN or a hardware compression net module for the ASN in which case the default is Hardware Software Hardware Determines whether compression for this node will be software or hardware based You can use hardware compression with Frame Relay and PPP only You can use software compression with Frame Relay PPP or X 25 Select Software to use software based compression or select Hardware
19. ameter to Disable Reset it to Enable to reenable WCP 1 3 6 1 4 1 18 3 4 22 2 1 2 117352 A Rev A A 5 Configuring Data Compression Services Parameter Path Default Options Function Instructions MIB Object ID Compression Mode Configuration Manager Protocols WCP Interfaces Inherit from Line Continuous Packet Packet by Packet Inherit from Line Indicates the compression mode on the circuit Continuous packet compression CPC retains compression history across packets and allows a higher compression ratio than does packet by packet compression PPC PPC resets compression history at the start of each packet resulting in a lower compression ratio Since PPC does not depend on previous packets you should select this option for a link that drops a large number of packets Inherit from Line allows you to set WCP parameters at the line level and apply them to circuits For PPP with only one circuit per line this means that you can configure WCP at either the circuit level or the line level Select Inherit from Line if you want to accept the value in effect for the WCP Compression Mode line parameter Otherwise select either Continuous Packet or Packet by Packet 1 3 6 1 4 1 18 3 4 22 2 1 4 A 6 117352 A Rev A Parameter Path Default Options Function Instructions MIB Object ID Data Compression Parameters History Size Configuration Manager Protocols WCP
20. arameters A 5 to A 8 Compression Control Protocol CCP definition 2 2 initialization 2 6 negotiations 2 7 compression modes 3 1 compression ratio 2 3 configuring hardware compression 1 2 software compression 1 1 contexts for hardware compression 2 4 customer support programs xvi Technical Solutions Centers xvi D data compression allocating memory 3 1 architecture 2 2 deleting from a router 1 4 features 2 12 117352 A Rev A Index modes continuous 3 1 packet by packet 3 1 overview 2 1 to 2 12 performance 2 3 starting 1 1 to 1 3 daughterboards for hardware compression 2 4 deleting compression 1 4 dial backup 2 10 Frame Relay 2 8 dial on demand 2 10 E enabling data compression 1 1 to 1 3 F fallback compression mode 3 6 Frame Relay data compression features 2 8 dial backup 2 8 hybrid mode 2 8 multiline 2 9 H hardware compression configuring 1 2 contexts 2 4 daughterboards and net modules 2 3 history buffer 2 2 history size 3 2 Index 1 L Lempel Ziv LZ 77 algorithm 2 2 line parameters A 1 to A 5 Max Window Size parameter X 25 2 11 maximizing compression 3 1 multiline 2 9 multilink 2 10 net modules for hardware compression 2 4 Network Control Protocol NCP negotiations 2 6 2 7 P parameters circuit interface A 5 to A 8 line A 1 to A 5 performance 2 3 PPP bandwidth on demand 2 10 data compression features 2 9
21. arates menu and option names in instructions and internal pin to pin wire connections Example Protocols gt AppleTalk identifies the AppleTalk option in the Protocols menu Example Pin 7 19 20 Indicates that you enter only one of the parts of the command The vertical line separates choices Do not type the vertical line when entering the command Example If the command syntax is show at routes nets you enter either show at routes or show at nets but not both Xiv 117352 A Rev A Acronyms CCP CPC CRC DDN IETF ILI LCP MIB NCP PDN PPC PPP PtoP PVC RFC VC WAN WCP About This Guide Compression Control Protocol continuous packet compression cyclic redundancy check Defense Data Network Internet Engineering Task Force Intelligent Link Interface Link Control Protocol management information base Network Control Protocol Public Data Network packet by packet compression Point to Point Protocol Point to Point Protocol proprietary to Bay Networks permanent virtual circuit Request for Comments virtual circuit wide area network WAN Compression Protocol Ordering Bay Networks Publications To purchase additional copies of this document or other Bay Networks publications order by part number from Bay Networks Press at the following numbers e Phone U S Canada 1 888 422 9773 e Phone International 1 510 490 4752 e FAX U S Canada and International 1 510 498 2609 117352 A
22. ck Compression Mode Fallback compression mode is configurable on a line basis only Use it to indicate the compression mode that you want to use when no hardware compression contexts are available The options are Software CPC and Hardware PPC Software CPC is a good choice for lower speed links 64 Kb s or less It generally affords a better compression ratio than does Hardware PPC Hardware PPC is a good choice for higher speed links greater than 64 Kb s It provides better throughput than does Software CPC Site Manager Fallback Compression Mode parameter page A 5 3 6 117352 A Rev A Appendix A Data Compression Parameters WCP Line Parameters Parameter Path Default Options Function Instructions MIB Object ID Use the following descriptions to set Bay Networks data compression line parameters Notice that the Site Manager path for all line parameters is the same as is the path for all circuit interface parameters This means that you can edit all line parameters or all interface parameters at the same time Enable Configuration Manager gt Protocols gt WCP gt Lines Enable Enable Disable Enables or disables data compression on the line WCP automatically sets this parameter to Enable when you select WCP in the Select Protocols window If you want to temporarily disable WCP rather than delete it from the platform set this parameter to Disable Reset it to Enable to reenable WCP 1
23. copy in whole or in part Except as expressly provided in this Agreement Licensee may not copy or transfer the Software or user manuals in whole or in part The Software and user manuals embody Bay Networks and its licensors confidential and proprietary intellectual property Licensee shall not sublicense assign or otherwise disclose to any third party the Software or any information about the operation design performance or implementation of the Software and user manuals that is confidential to Bay Networks and its licensors however Licensee may grant permission to its consultants subcontractors and agents to use the Software at Licensee s facility provided they have agreed to use the Software only in accordance with the terms of this license 3 Limited warranty Bay Networks warrants each item of Software as delivered by Bay Networks and properly installed and operated on Bay Networks hardware or other equipment it is originally licensed for to function substantially as described in its accompanying user manual during its warranty period which begins on the date Software is first shipped to Licensee If any item of Software fails to so function during its warranty period as the sole remedy Bay Networks will at its discretion provide a suitable fix patch or workaround for the problem that may be included in a future Software release Bay Networks further warrants to Licensee that the media on which the Software is provided will be fr
24. ee from defects in materials and workmanship under normal use for a period of 90 days from the date Software is first shipped to Licensee Bay Networks will replace defective media at no charge if it is returned to Bay Networks during the warranty period along with proof of the date of shipment This warranty does not apply if the media has been damaged as a result of accident misuse or abuse The Licensee assumes all responsibility for selection of the Software to achieve Licensee s intended results and for the installation use and results obtained from the Software Bay Networks does not warrant a that the functions contained in the software will meet the Licensee s requirements b that the Software will operate in the hardware or software combinations that the Licensee may select c that the operation of the Software will be uninterrupted or error free or d that all defects in the operation of the Software will be corrected Bay Networks is not obligated to remedy any Software defect that cannot be reproduced with the latest Software release These warranties do not apply to the Software if it has been i altered except by Bay Networks or in accordance with its instructions ii used in conjunction with another vendor s product resulting in the defect or iii damaged by improper environment abuse misuse accident or negligence THE FOREGOING WARRANTIES AND LIMITATIONS ARE EXCLUSIVE REMEDIES AND ARE IN LIEU OF ALL OTHER WARRANTIES EXPRES
25. ettings for compression line and interface parameters Chapter 3 See a list of default parameter settings Appendix A Before You Begin Before using this guide you must complete the following procedures For a new router e Install the router refer to the installation manual that came with your router e Connect the router to the network and create a pilot configuration file refer to Quick Starting Routers Configuring BayStack Remote Access or Connecting ASN Routers to a Network Make sure that you are running the latest version of Bay Networks Site Manager and router software For instructions refer to Upgrading Routers from Version 7 11 xx to Version 12 00 117352 A Rev A xiii Configuring Data Compression Services Conventions bold text italic text quotation marks screen text separator gt vertical line Indicates text that you need to enter command names and buttons in menu paths Example Enter wfsm amp Example Use the dinfo command Example ATM DXI gt Interfaces gt PVCs identifies the PVCs button in the window that appears when you select the Interfaces option from the ATM DXI menu Indicates variable values in command syntax descriptions new terms file and directory names and book titles Indicate the title of a chapter or section within a book Indicates data that appears on the screen Example Set Bay Networks Trap Monitor Filters Sep
26. ion ACK 3 WCP negotiations complete begin NCP negotiations Send Configure Request m Send Configure Request Send Configure ACK e Send Configure ACK 4 NCP open begin transmitting data lt lt Send Data DC0001A Figure 2 1 CCP WCP and NCP Initialization on a PPP Link 2 6 117352 A Rev A Data Compression Overview CCP Negotiations CCP allows the two ends of a PPP connection to negotiate whether to use data compression and if so which algorithm to use Our implementation of compression uses only the LZ 77 algorithm Note If one side of a link requests an algorithm that the other side does not support traffic over the link continues but in uncompressed form In the example shown in Figure 2 1 negotiations begin when PPP establishes a link CCP uses the same configuration and network control protocol negotiations that the Link Control Protocol LCP uses For a detailed explanation of LCP negotiations see Establishing the PPP Link in Configuring PPP Services WCP Negotiations Frame Relay and X 25 use WCP to negotiate whether to use data compression and which algorithm to use As with PPP if one side of a link requests an algorithm that the other side does not support traffic continues but in uncompressed form Each side of a link running data compression has a compressor a decompressor a compression history and a retransmission buffer When you configure compression yo
27. mpression engine can find a data pattern match up to three times faster using a 32 KB history than an 8 KB history If you select different history sizes for the two sides of a link the smaller of the two becomes the effective history size Inherit from Line allows you to set WCP parameters at the line level and apply them to circuits Select Inherit from Line if you want to accept the value in effect for the WCP History Size line parameter Otherwise select either 32 K or 8 K 1 3 6 1 4 1 18 3 4 22 2 1 5 117352 A Rev A A 7 Configuring Data Compression Services Parameter Path Default Options Function Instructions MIB Object ID Engine Type Configuration Manager gt Protocols gt WCP gt Interfaces Inherit from Line Software Hardware Inherit from Line Determines whether compression for this node will be software or hardware based You can use hardware compression with Frame Relay and PPP only You can use software compression with Frame Relay PPP or X 25 Select Inherit from Line if you want to accept the value in effect for the WCP Engine Type line parameter Otherwise select Software to use software based compression or select Hardware to use Hardware based compression 1 3 6 1 4 1 18 3 4 22 2 1 6 A 8 117352 A Rev A A allocating memory 3 1 B bandwidth on demand 2 10 Bay Networks Press xv Bay Networks World Wide Web page xvii buffer size 3 4 C circuit interface p
28. o dual and quad synchronous MCEI ISDN PRI MCTI ISDN dual sync with ISDN BRI and QBRI net modules One compression net module in a single ASN can provide hardware compression for all the net modules on that router It does not provide compression for any other ASNs in the stack The compression net module is available in both a 32 contexts and a 128 contexts version The compression net modules for the ASN are e AF2104007 a 32 contexts hardware compression net module e AF2104012 a 128 contexts hardware compression net module Hardware Compression Contexts A context refers to compression and decompression for a single virtual circuit VC Compression hardware maps a context to specific regions of compression and decompression memory If you have a 32 contexts compression daughterboard or net module you can simultaneously run compression over 31 continuous packet compression CPC contexts each using an 8 KB history size with one shared 8 KB packet by packet compression PPC context If you have a 128 contexts compression daughterboard or net module you can simultaneously run compression over 127 CPC contexts each using an 8 KB history size with one shared 8 KB PPC context For more information on CPC and PPC see Chapter 3 2 4 117352 A Rev A Data Compression Overview The only difference between the 32 contexts and 128 contexts Bay Networks compression daughterboards and net modules is that the 128 contexts daugh
29. pression net module compresses data transmitted over a WAN network by dual and quad synchronous MCE1 ISDN PRI MCTI ISDN dual sync with ISDN BRI and QBRI net modules Hardware compression supports all of the PPP services that software compression supports Bay Networks software and hardware based compression interoperate fully because they use the same algorithm To use data compression effectively you must decide how to allocate memory for this task The goal is to compress data as much as possible and to transmit the data as quickly as possible without unduly taxing the resources of the router 117352 A Rev A 2 1 Configuring Data Compression Services Data Compression Architecture Bay Networks uses the following algorithm and protocols to provide data compression services e LZ 77 algorithm e Compression Control Protocol draft RFC e Bay Networks proprietary compression protocol WCP LZ 77 Algorithm We base our data compression on a Lempel Ziv LZ 77 algorithm The algorithm uses a sliding history buffer that stores the data that the network link has processed most recently The compressor compares new data strings with data it has already processed and stored in the buffer When the compressor detects data strings that match data it has already processed it replaces those strings with offset and length tokens that are shorter than the original strings thus compressing the data Compression Control Protocol CCP
30. r Frame Relay you must configure compression on the backup circuit because with either a shared or secondary configuration the backup PVCs can use different configurations from the primary For further information on Bay Networks dial services refer to Configuring Dial Services Frame Relay Multiline Multiline is a feature that enables you to configure a single circuit that consists of one or more WAN data paths A data path is a logical point to point channel it can be a permanent or dial up physical line or it can be a virtual circuit connection Multiline provides both increased fault tolerance and greater bandwidth between two sites For more information about Bay Networks multiline refer to Configuring WAN Line Services PPP Services You can use software or hardware data compression on all PPP circuits including multiline and multilink bandwidth on demand dial on demand and dial backup lines When you use compression on a bandwidth on demand dial on demand or dial backup circuit WCP automatically configures or deletes compression as lines are added to or removed from the circuit PPP Multiline Multiline is a feature that enables you to configure a single circuit that consists of one or more WAN data paths A data path is a logical point to point channel it can be a permanent or dial up physical line or it can be a virtual circuit connection Multiline provides both increased fault tolerance and greater bandwidth bet
31. r Software Restricted Rights clause of FAR 52 227 19 and the limitations set out in this license for civilian agencies and subparagraph c 1 ii of the Rights in Technical Data and Computer Software clause of DFARS 252 227 7013 for agencies of the Department of Defense or their successors whichever is applicable 6 Use of Software in the European Community This provision applies to all Software acquired for use within the European Community If Licensee uses the Software within a country in the European Community the Software Directive enacted by the Council of European Communities Directive dated 14 May 1991 will apply to the examination of the Software to facilitate interoperability Licensee agrees to notify Bay Networks of any such intended examination of the Software and may procure support and assistance from Bay Networks 7 Term and termination This license is effective until terminated however all of the restrictions with respect to Bay Networks copyright in the Software and user manuals will cease being effective at the date of expiration of the Bay Networks copyright those restrictions relating to use and disclosure of Bay Networks confidential information shall continue in effect Licensee may terminate this license at any time The license will automatically terminate if Licensee fails to comply with any of the terms and conditions of the license Upon termination for any reason Licensee will immediately destroy or return to Ba
32. r further information about these steps refer to Configuring and Managing Routers with Site Manager Configuring Hardware Compression To use hardware compression you must have an octal sync link module with a hardware compression daughterboard for the BN or a hardware compression net module for the ASN You can use hardware compression with Frame Relay and PPP Configuring Compression for the Backbone Node BN To configure hardware compression for the BN 1 Select either AG2104037 or AG2104038 These are the octal sync link modules with hardware compression daughterboards 2 Select a port 3 Specify Frame Relay or PPP as the WAN protocol Site Manager Path From the Protocols window that appears after you select the port select PPP or Frame Relay Click on OK The Select Protocols window appears Configuring Compression for the Access Stack Node ASN To configure hardware compression for the ASN 1 Select either AG2104007 or AF2104012 These are the hardware compression net modules for the ASN 2 Select a WAN connector on the same slot 3 Select a port 4 Specify Frame Relay or PPP as the WAN protocol Site Manager Path From the Protocols window that appears after you select the port select PPP or Frame Relay Click on OK The Select Protocols window appears 1 2 117352 A Rev A Starting Compression Note If you have a hardware compression net module on an ASN you can use ha
33. r links with speeds higher than 64 Kb s to improve throughput The compressor can find a data pattern match up to three times faster using a 32 KB history than an 8 KB history 3 2 117352 A Rev A Customizing Data Compression History Size with Hardware Compression Hardware compression daughterboards and net modules are available in 32 and 128 contexts The numbers 32 and 128 assume a history size of 8 KB per context although you can configure history size at either 8 KB or 32 KB For example if you configure history size at 32 KB you have used four 8 KB contexts and you have that many fewer contexts available to run hardware compression on your network Note Although software compression does not put strict limits on the number of contexts you can configure be aware that memory requirements for history size are the same for software and hardware compression Both boards reserve one 8 KB context for PPC as opposed to CPC There is no limit to the number of VCs that can use this one PPC context The maximum number of VCs for the compression engine is 256 The compression hardware uses memory in units called pages where a page equals 32 KB of memory Each context that uses a 32 KB history uses one page of memory Restrictions for CPC contexts using either 8 or 32 KB histories are that the memory used for any one history must be continuous and it may not cross pages For 8 KB contexts these restrictions create few const
34. raints but for 32 KB contexts they are significant Thirty one CPC contexts each using an 8 KB history are possible on the 32 context board and 127 contexts each using an 8 KB history are possible on the 128 context board Table 3 1 indicates the maximum number of 8 KB contexts each board can support Table 3 4 Hardware Compression 8 KB Contexts Max 8 KB CPC Available 32 KB Reserved 8 KB Contexts CPC Contexts PPC Context 32 Context Board 31 0 1 128 Context Board 127 0 1 On a 32 context board the maximum number of 32 KB contexts is 7 and on a 128 context board the maximum number of 32 KB contexts is 31 because of the 8 KB of memory the one PPC context requires Table 3 2 summarizes this information 117352 A Rev A 3 3 Configuring Data Compression Services Table 3 2 Hardware Compression 32 KB Contexts Max 32 KB CPC Available 8 KB Reserved 8 KB PPC Contexts CPC Contexts Context 32 Context Board T 3 1 128 Context Board 31 3 1 You can mix 8 KB and 32 KB contexts on either board Be aware that if you are bringing VCs up and down memory may fragment Even though you have 32 or more KB of compression memory available if it is on different pages you will not be able to configure a 32 KB context To solve this problem you must save your configuration and reset the slot When you reset the slot available compression memory is rearranged to be contiguous If you have memory available you are
35. rdware compression on any WAN port on that single router or slot Hardware compression on the ASN does not work across slots that is it does not provide compression for any other ASNs in the stack Starting Data Compression You enable data compression for PPP and Frame Relay differently from X 25 Starting Data Compression for Frame Relay and PPP Enable WCP You can also enable other protocols that you want to configure Site Manager Path In the Select Protocols window scroll down to select WCP Click on OK Starting Data Compression for X 25 You enable WCP only after you have added a service record You can also enable other protocols at the same time Site Manager Path After you have configured a service record in the Service Record Window select Protocols Add Delete The Select Protocols window appears Scroll down to select WCP Click on OK You must also enable the X 25 service record compression parameter for each X 25 interface that you configure See Configuring X 25 Services for further information about X 25 service records Finding Further Information For detailed information on Bay Networks data compression refer to Chapter 2 For information and recommendations about using nondefault values refer to Chapter 3 117352 A Rev A Configuring Data Compression Services Deleting Data Compression from a Platform To delete WCP from all circuits on the router follow this Si
36. res You can configure both software and hardware based compression Onacircuit or line basis e With multiline and multilink Features specific to software and hardware compression follow 117352 A Rev A 2 11 Configuring Data Compression Services Software Based Data Compression Software based data compression works over WAN links running Frame Relay PPP or X 25 It includes Compression for a FRE module at 4 x 128 KB s compressed throughput full duplex or 512 KB s aggregate compressed throughput Compression on an Access Node ANS platform at 2 x 64 KB s compressed throughput full duplex or 128 KB s aggregate compressed throughput Compression on all intelligent link interface modules ILIs that support serial and ISDN BRI ports Support for all Bay Networks platforms AN ASN and BN plus VME Compression on MCT 1 and MCE 1 lines Hardware Based Data Compression Hardware compression works over WAN links running Frame Relay and PPP Hardware compression is available as Optional daughterboards for Frame Relay and PPP networks that use the octal synchronous link module for the BN using FRE 2 processors only Optional net modules for Frame Relay and PPP networks that use the ASN Hardware compression can compress data transmitted over WANs attached to dual and quad synchronous MCE1 ISDN PRI MCTI ISDN dual sync with ISDN BRI and QBRI net modules 2 12 117352 A Rev A Chapter 3 Customizing Data Comp
37. ression When you enable data compression default values are in effect for all parameters see parameter descriptions in Appendix A You may want to change these values depending on the requirements of your network The following sections provide information about Bay Networks compression and decisions you make to use compression effectively on your network Allocating Compression Memory Using compression on your network involves allocating memory to maximize compression without unduly taxing the resources of your system You can select Acompression mode to maximize compression ratio e A history size to maximize throughput e A buffer size to prevent data loss Maximizing Compression Ratio You can compress data in one of two modes e Continuous packet compression CPC maintains compression history across packets CPC yields a higher compression ratio than does packet by packet In most circumstances you should select CPC the default value to maximize compression e Packet by packet compression PPC creates a new history for each packet PPC yields a lower compression ratio than does CPC Select PPC only for links that drop a very large number of packets Be aware that under these circumstances implementing data compression may offer marginal or no advantages 117352 A Rev A 3 1 Configuring Data Compression Services If either side of the link specifies PPC both sides of the link use PPC Site Manager
38. se zi Compression EE 3 1 Maximizing Throughput GES NEEN T ETTER TORT RE E SKE Heavy ale TEES 3 2 S2 RE np cic de i NER TE T E 3 2 History Size with Hardware Compression nee 3 3 Preventing Data Loss for Frame Relay and PPP 3 4 vi 117352 A Rev A Gontiguring Hardware Gompressin x bep ette a gc teca a E a 3 5 Selecting Software or Hardware Compression Engines sss 3 5 Selecting a Fallback Compression Mode un anna 3 6 Appendix A Data Compression Parameters WOP Line Parameters EEEE EHE QUAD TEN A 1 WOP Circuit Interface Parameters nenne A 5 Index 117352 A Rev A vii Figures Figure 2 1 CCP WCP and NCP Initialization on a PPP Link usesesssse 2 6 117352 A Rev A ix Tables Table 3 1 Hardware Compression 8 KB Contexts ssssseeee 3 3 Table 3 2 Hardware Compression 32 KB Contexts sss 3 4 117352 A Rev A xi About This Guide If you are responsible for configuring and managing Bay Networks routers and or BayStream switching platforms running over Frame Relay Point to Point or X 25 networks you need to read this guide to learn how to customize Bay Networks platforms for software and hardware based data compression If you want to Go to Start compression Chapter 1 Learn about data compression services Chapter 2 Change default s
39. sion software therefore ignores the Buffer Size parameter for X 25 so if you are configuring compression for X 25 you do not need to set this parameter Site Manager Buffer Size parameter page A 4 line Configuring Hardware Compression There are two issues specific to hardware compression Selecting Software or Hardware Compression Engines When you configure a VC for compression the default compression type varies The default is software compression for link modules that do not support hardware compression for those that do the default is hardware refer to Hardware Compression in Chapter 2 The default for a net module is software compression unless the ASN has a hardware compression net module If an ASN has a hardware compression net module the default is hardware You can use software compression even though you are using a hardware compression daughterboard or net module Bay Networks recommends that you use hardware compression for connections greater than 512 Kb s You would also want to specify software compression for VCs in excess of the number of contexts your hardware compression daughterboard or net module can support Configure a VC to use software compression by setting the Engine Type parameter to software Site Manager Engine Type parameter page A 4 line page A 8 circuit interface 117352 A Rev A 3 5 Configuring Data Compression Services Selecting a Fallba
40. such portions of the software were developed by the University of California Berkeley The name of the University may not be used to endorse or promote products derived from such portions of the software without specific prior written permission SUCH PORTIONS OF THE SOFTWARE ARE PROVIDED AS IS AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE In addition the program and information contained herein are licensed only pursuant to a license agreement that contains restrictions on use and disclosure that may incorporate by reference certain limitations and notices imposed by third parties ii 117352 A Rev A Bay Networks Inc Software License Agreement NOTICE Please carefully read this license agreement before copying or using the accompanying software or installing the hardware unit with pre enabled software each of which is referred to as Software in this Agreement BY COPYING OR USING THE SOFTWARE YOU ACCEPT ALL OF THE TERMS AND CONDITIONS OF THIS LICENSE AGREEMENT THE TERMS EXPRESSED IN THIS AGREEMENT ARE THE ONLY TERMS UNDER WHICH BAY NETWORKS WILL PERMIT YOU TO USE THE SOFTWARE If you do not accept these terms and conditions return the product unused and in the original shipping container within 30 days of purchase to obtain a credit for the full purchase price 1 License Grant Bay Networks Inc Bay Networks
41. t both the bridged and the routed traffic over that circuit are compressed Note that compression applies only to the hybrid PVC and not to the other PVCs from the main circuit unless you have also enabled compression for those interfaces Conversely if you enable data compression for other PVCs but not on a PVC you have configured for hybrid mode the hybrid circuit does not use compression Frame Relay Dial Backup Frame Relay enables you to configure a dial backup feature If a primary Frame Relay circuit fails and you have enabled dial backup the router automatically establishes a backup circuit The backup circuit can be PPP or Frame Relay for a Frame Relay service record with only one PVC The backup circuit is Frame Relay for a Frame Relay service record with two or more PVCs 2 8 117352 A Rev A Data Compression Overview The backup circuit can inherit the primary s configuration or it can use its own When the Frame Relay primary and backup use the same configuration they have a shared configuration The backup circuit uses the same network layer address as the primary circuit The data link layer configuration that is the backup PVCs DLCIs and filters can be the same or different from the primary If the backup uses a unique configuration it is a secondary configuration A secondary configuration uses a different network layer address PVCs and filters from the primary To use data compression with dial backup fo
42. te Manager path Site Manager Path Configuration Manager gt Protocols gt WCP gt Delete WCP A window appears and prompts Do you REALLY want to delete WCP Click on OK Site Manager returns you to the Configuration Manager window WCP is no longer operating on the platform 1 4 117352 A Rev A Chapter 2 Data Compression Overview Bay Networks data compression services enable you to reduce line costs and improve response times over wide area networks Our data compression eliminates redundancies in data streams When you use compression on your network bandwidth efficiency improves and you can transmit more data over a given amount of network bandwidth Our compression services include e Software based compression for Frame Relay Point to Point Protocol PPP and X 25 networks for all router platforms and all serial interfaces This includes PPP compression on multiline multilink on the ISDN BRI and PRI modules and on interfaces that use raise DTR or V 25 bis signaling with dial services It also includes Frame Relay compression on multiline and dial backup e Hardware based compression for Frame Relay and PPP networks that use the octal synchronous link module for the BN using Fast Routing Engine 2 FRE 2 processors Hardware compression supports all of the PPP and Frame Relay services that software compression supports e Hardware based compression for Frame Relay and PPP networks for the ASN A com
43. terboard and net module have more memory 2 MB compression 1 MB decompression as opposed to 512 KB compression 256 KB decompression for the 32 contexts daughterboard and net module Note You should plan your network to use hardware compression on the VCs most important to you within the limits of your equipment If you configure more VCs for hardware compression than your daughterboard or net module can support you have no way of controlling which VCs will in fact use hardware compression By default all VCs that exceed the hardware context limit use software compression For more information see Chapter 3 How Data Compression Works The following sections describe how Bay Networks data compression works As you read these sections refer to Figure 2 1 which illustrates CCP and WCP initialization on a PPP link 117352 A Rev A 2 5 Configuring Data Compression Services El jJ e Router A Router B 1 PPP interface on network LCP negotiations complete begin CCP negotiations Send Initialization Request p EE Send Initialization Request Send Initialization ACK Z ee Send Initialization ACK 2 CCP negotiations complete begin WCP negotiations including compression mode history size and buffer size Send Initialization Request e Send Initialization Request Send Initialization ACK T Ka Send Initializat
44. to use hardware based compression 1 3 6 1 4 1 18 3 4 22 1 1 8 A 4 117352 A Rev A Parameter Path Default Options Function Instructions MIB Object ID Data Compression Parameters Fallback Compression Mode Configuration Manager gt Protocols gt WCP gt Lines Software CPC Software CPC Hardware PPC This parameter is for hardware compression only Use it to indicate the compression mode you want to use when no hardware compression contexts are available Software CPC is a good choice for lower speed links 64 Kb s or less It generally affords a better compression ratio than does Hardware PPC Hardware PPC is a good choice for higher speed links greater than 64 Kb s It provides better throughput than does Software CPC Refer to Chapter 1 for explanations of continuous packet and packet by packet compression modes Select Software CPC or Hardware PPC 1 3 6 1 4 1 18 3 4 22 1 1 10 WCP Circuit Interface Parameters Parameter Path Default Options Function Instructions MIB Object ID Use the following descriptions to set Bay Networks data compression Enable Configuration Manager gt Protocols gt WCP gt Interfaces Enable Enable Disable Enables or disables data compression on the line WCP automatically sets this parameter to Enable when you select WCP in the Select Protocols window If you want to temporarily disable WCP rather than delete it from the platform set this par
45. u can edit WCP parameters for compression mode history size and buffer size to optimize compression performance on your network Data Transmission Frame Relay and X 25 data transmission using compression begins when WCP negotiations are complete For PPP Network Control Protocol NCP negotiations and WCP negotiations occur simultaneously When PPP NCP and WCP negotiations are complete data transmission using compression begins 117352 A Rev A 2 7 Configuring Data Compression Services Compression Features for Specific Protocols Bay Networks data compression services vary in some details according to the WAN protocols that you configure Read the following sections to learn about how our implementation of data compression applies to Frame Relay PPP and X 25 services Frame Relay Services You can use software or hardware based data compression with Frame Relay You can use compression with some VCs and not with others as you choose both for regular Frame Relay VCs and for those you configure in hybrid mode You can also use compression with dial backup You must enable compression on both sides of a Frame Relay link If you enable data compression on only one side of the link data transmission occurs but in uncompressed form Frame Relay Hybrid Access Hybrid access enables you to combine bridging and routing over a single Frame Relay interface When you enable data compression for Frame Relay on a hybrid circui
46. ween two sites 117352 A Rev A 2 9 Configuring Data Compression Services For more information about Bay Networks multiline see Configuring WAN Line Services PPP Multilink The multilink feature of PPP provides capabilities beyond those of multiline circuits Multilink consists of a bundle of lines between two peers consisting of up to four links Multilink can e Distribute traffic across the lines in the bundle in amounts roughly proportional to the effective bandwidth of each link e Use lines that have different speeds proportionally distributing traffic over those lines e Balance traffic load and restore packet sequence e Use switched lines such as ISDN B channels as well as leased lines e Monitor traffic volume PPP Bandwidth on Demand Bandwidth on demand allows a secondary dial up line to augment a primary leased line when the primary line experiences congestion Congestion occurs when traffic volume exceeds line capacity When congestion abates the secondary line becomes inactive PPP Dial on Demand Dial on demand enables you to establish a circuit only when you want to transmit and receive data as opposed to having a leased line which is always available By using a circuit on a demand basis you can significantly reduce your line costs PPP Dial Backup PPP also allows you to configure a dial backup feature If a primary PPP line fails and you have enabled dial backup the router automatically
47. y Networks the Software user manuals and all copies Bay Networks is not liable to Licensee for damages in any form solely by reason of the termination of this license 8 Export and Re export Licensee agrees not to export directly or indirectly the Software or related technical data or information without first obtaining any required export licenses or other governmental approvals Without limiting the foregoing Licensee on behalf of itself and its subsidiaries and affiliates agrees that it will not without first obtaining all export licenses and approvals required by the U S Government 1 export re export transfer or divert any such Software or technical data or any direct product thereof to any country to which such exports or re exports are restricted or embargoed under United States export control laws and regulations or to any national or resident of such restricted or embargoed countries or ii provide the Software or related technical data or information to any military end user or for any military end use including the design development or production of any chemical nuclear or biological weapons 9 General If any provision of this Agreement is held to be invalid or unenforceable by a court of competent jurisdiction the remainder of the provisions of this Agreement shall remain in full force and effect This Agreement will be governed by the laws of the state of California Should you have any questions concerning this
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