Cisco Systems Network Router manual Planning Guidelines for Individual Peer Groups

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Chapter 2 Interoperability and Performance Planning

Planning Guidelines for Individual Peer Groups

Multiple Links Between Adjacent Peer Groups

Communications between two peer groups takes place through two border nodes. Parallel links between two border nodes improves reliability. Adding additional border nodes to handle communications between two peer groups provides alternative routing paths and prevents network outages caused by a single node failure.

Multiple Links to an External Network

An external network link is any non-PNNI network link. External network links include AINI and IISP links. As with internal network links, consider using parallel links and additional border nodes to provide alternative paths to external networks. When you configure multiple static links to an external network, remember to duplicate the ATM address advertisement configuration on all redundant links.

Multiple Paths Between Network Nodes

It is good design practice to ensure that there are at least two different paths between any pair of nodes that will communicate with each other. A pair of redundant links is one path. If one switch site is damaged by fire or earthquake, there should be at least one other switch that can provide an alternative path between the source and destination switches.

It is also a good design practice to distribute paths across multiple service modules so that a service module failure does not disrupt all communications between two nodes.

Planning Guidelines for Individual Peer Groups

The first step in planning a PNNI topology is to determine if all network nodes will participate in one peer group or in hierarchical peer groups. The single and hierarchical peer group topologies are introduced in Chapter 1, “Introduction to PNNI.” When a network grows beyond the capabilities of a single peer group, you must use the hierarchical peer group topology.

The planning for a single peer group topology is the same as the planning for a single peer group within a hierarchical PNNI network. The difference between planning for a single peer group network and planning for a hierarchical network is that for hierarchical networks, you have to plan the communications between peer groups. The following list summarizes the capabilities and guidelines for a single peer group:

•For networks with less than 100 nodes, Cisco Systems recommends using a single peer group topology.

•A single peer group supports up to 160 nodes as described in Table 2-1.

•All nodes within a single peer group must be able to communicate with each other over a path of inside links.

•PNNI can route calls through a maximum of 20 nodes within a single peer group. The structure of the peer group should be such that no node is more than 19 hops from any other node.

•As the number of nodes in a single peer group grows, the network and system resource requirements for each node grows.

 

Cisco PNNI Network Planning Guide for MGX and SES Products, Release 5

2-6

Part Number OL-3847-01 Rev. D0, April, 2004

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Contents Corporate Headquarters Text Part Number OL-3847-01 Rev. D0Copyright 2003, Cisco Systems, Inc All rights reserved N T E N T S IiiCompatible Standards Worksheets Part Number OL-3847-01 Rev. D0, April G U R E S ViiViii B L E S Part Number OL-3847-01 Rev. D0, April Objectives AudienceOrganization Conventions XiiDocumentation Documentation Notes for the April 2004 Product ReleasesRelated Documentation XiiiTechnical Manual Order of Use XivTechnical Manual Titles and Descriptions TermsXvi Xvii Xviii Xix Reference Guides Xxi Document Title Description XxiiXxiii Xxiv Xxv Xxvi Obtaining Documentation Cisco.comOrdering Documentation XxviiChanges to This Document Chapter ChangesXxviii Obtaining Technical Assistance Documentation FeedbackCisco TAC Website Opening a TAC CaseObtaining Additional Publications and Information TAC Case Priority DefinitionsXxx Xxxi Xxxii Introduction to Pnni Pnni Network DatabaseSingle Peer Group Topology Hierarchical Pnni Network Topology Example Single Peer Group TopologyPeer group Ppeer Peer Group Leaders Simple Node RepresentationComplex Node Representation Simple Node RepresentationPnni Internetworking with Aini Border NodesHierarchical Pnni Network Benefits Pnni Internetworking with Iisp Example Pnni Internetworking with Aini TopologyPart Number OL-3847-01 Rev. D0, April Specifications Compatible StandardsPXM45 CapabilitiesPXM1E PXM45/BCapabilities SES SESConnection Limit Adjustments Connection Type Switch Connections CWM EndpointsSVC DAX SpvcInstall Redundant Hardware in Switches Parallel Links Between Adjacent SwitchesPhysical Network Planning Planning Guidelines for Individual Peer Groups Multiple Links Between Adjacent Peer GroupsMultiple Links to an External Network Multiple Paths Between Network NodesPlanning Guidelines for Hierarchical Networks Planning Guidelines for Peer Group LeadersPlanning Guidelines for Border Nodes Part Number OL-3847-01 Rev. D0, April Address and Closed User Group Planning Address Planning OverviewPnni Addressing Example Planning Address Configuration Settings Selecting an ATM Address FormatSupported Address Formats ESI SEL IDP DSPATM Field Description Default Values Guidelines for Selecting an Address FormatSelecting a Pnni Level Address Registration AuthoritiesCategory Type Authorities DCC4shows an example topology of a Pnni MPG WAN Part Number OL-3847-01 Rev. D0, April Length Level Peer Group ID Portion of ATM Address BytesDefault Peer Group ID Selecting the Pnni Peer Group IDSelecting the ATM Address 20-byte Node AddressSelecting the Ilmi Address Prefix Selecting the Spvc Address PrefixPlanning Address Prefixes for Aini and Iisp Links Selecting Static Addresses for UNI Ports Additional Guidelines for Creating an Address PlanClosed User Group Overview Closed User Group ExamplePlanning CUG Configuration Settings Selecting an Interlock CodeSelecting an Index Selecting Internal CUG Access Options Selecting CPE AddressesSelecting External CUG Access Options Specifying a Preferential CUGSelecting a Default CUG Address WorksheetsCUG Part Number OL-3847-01 Rev. D0, April Administrative Weight How MGX and SES Nodes Select RoutesLink and Route Metrics Cell Transfer Delay Cell Delay VariationAvailable Cell Rate Shortest Path Table Routing Maximum Cell RateShortest Path Tables Class of Service Tables Service Class Acronym Definition GuidelinesCTD CDV Traffic MetricHow SVCs and SVPs use the SPTs How SPVCs and SPVPs use the SPTsHow MGX and SES Nodes Select Links On-Demand RoutingLoad Balancing for SPT and On-Demand Routing Additional Routing Features in MGX and SES Nodes ServicePreferred Routing CLR0+12Priority Routing GroomingSoft Rerouting Priority BumpingBlocking Pass-Through Connections Nodal Point-to-Multipoint Branch RestrictionAXSM/A AXSM/BAXSM-E AXSM-XGFarthest Node Branching Part Number OL-3847-01 Rev. D0, April ABR AesaAini Ansi APSP2MP CBRCTD IN-2CUG CWMDIN IN-3IN-4 PGL PnniMGX SES IN-5IN-6 UBR UNITAC IN-7IN-8
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