Cisco Systems Cisco MGX 8850 cnfpnni-link-selection

5-24
Cisco MGX 8850 Routing Switch Command Reference
Release 2.0, Part Number 78-10467-04 Rev C0, October 2001
Chapter5 PNNI Commands
cnfpnni-link-selection
cnfpnni-link-selection
Configure PNNI Link Selection—specify the routing policies for parallel links.
The cnfpnni-link-selection command specifies which routing po l ici es a re used to select one of the
parallel links that connect a neighboring PNNI node. Neighboring node in this case means a directly
connected node. The cnfpnni-link-selection command applie s only if parallel links exis t be tween the
specified port and neighboring nodes.
Cards on Which This Command Runs
PXM45
Syntax
cnfpnni-link-selection <portid>
{minaw | maxavcr | maxcr | loadbalance}
Syntax Description
portid The portid is the PNNI physical port. Th e f o rm at is
[shelf.]slot[:subslot].port[:subport]. See also PNNI Format, page 5-5.
Default: no default port ID
minaw The routing protocol selects the link with the least administrative weight (AW).
The AW is a numeric value that every logical port ingress has. The to ta l co s t o f a
route is the sum of all ingress port AWs in both directions of the route.
The minaw policy is the default.
maxavcr The routing protocol se lects the link with the largest availa ble cell rate (AvCR).
The AvCR is the remaining bandwi dt h after the total utilized b an d w id th is
subtracted from the maximum cell rate (MaxC R).
The maxavcr policy works we ll fo r tr affic th at co n s ist ently requires a large
amount of bandwidth.
maxcr The routing protocol selects the link with the large st max imum cell rate (MaxCR ).
Typically, the MaxCR is the maximum speed of the line (or trunk). Therefore, if
one link traverses an OC3 line and another link traverses a T3 line, the MaxCR
policy dictates that PNNI sele ct t he OC3 line. Only when sufficien t b an d w id th
does not exist on a line does the routing protocol switch to AvCR.
The maxcr policy wo rk s w e l l for bursty traffic.
loadbalance The routing pr o tocol alternates the link it s ele cts for routing new calls. T he lo ad
balance policy works well w it h l in k s that have identical or very si mil ar AW or
bandwidth characteristics.