How Ip Channels Are Allocated; How Ilmi/Lmi Channels Are Allocated; How Ilmi Channels Are Allocated For Vsi Partitions On Trunk Interfaces; How Vsi Channels Are Assigned For Interslave Vcs - Cisco BPX-BXM-155-8DX Installation And Configuration Manual

Troubleshooting VSI Problems

How IP Channels are Allocated

IP channels are used for ALL5 messaging. The LCNs are reserved within switch software. The formula
for getting the LCN is num_chans + 14 + port (0 based). Twelve (12) LCNs are reserved for IP
channels, one for each port.

How ILMI/LMI Channels are Allocated

The formula for getting the LCN is num_chans + 2 + port.

How ILMI Channels are Allocated for VSI Partitions on Trunk Interfaces

When ILMI functionality is enabled for a VSI partition on a trunk interface, a new ILMI session is
started on the BXM card for the trunk interface. The LCN for this session is allocated from the LCNs
available for the AutoRoute partition. This LCN is allocated from the port-based pool; not from the
card-based pool.
Note that no new LCN is allocated when ILMI functionality is enabled for VSI partitions on port
interfaces. This is because the ILMI functionality for VSI partitions on port interfaces use the same
ILMI functionality that is started for AutoRoute. These use the pre-allocated LCN as discussed in the
preceding section.

How VSI Channels are Assigned for Interslave VCs

Interslave vcs are assigned with LCNs that are reserved within switch software. These lcns are not
taken from the pool. The formula for getting the lcn is num_chans + 26 + dest_slot where num_chans
is the number of channels the card supports

mc_vsi_end_lcn

This value is shown in the dsplogcd command. If the value is 0, then there are no vsi channels
configured on the card. If it is not zero, then there are VSI channels. It marks the first VSI channel.

num chans

This value is shown in the dsplogcd command as "Physical Chans". It is reported to switch software
from the card. Each BXM will vary in the number of channels that it supports.

How Port Group Enters the Channel Assignment Picture

The dsplogcd command is for service level users and above. You must have "service" level privileges
to use it.
There are some models of BXM cards which will support more than 1 port group. The command
dsplogcd
x channels, there is a hardward limitation of how many channels can be supported between certain ports.
A set of ports are grouped into port groups; that is, a BXM 8-port OC-3 card has two port groups,
consisting of ports 1–4, and 5–8 respectively. Each port group will have an upper limit of the number
of channels it can support, majority of the time it's
(num_chans / num_of_port_groups).
Cisco BPX 8600 Series Installation and Configuration
29-18
and will indicate the number of port groups supported. Even though each card supports
dspcd
Chapter 29
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
Troubleshooting