Merit Network
Can't find what you're looking for? Search the Mail Archives.
  About Merit   Services   Network   Resources & Support   Network Research   News   Events   Home

Discussion Communities: Merit Network Email List Archives

North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: sanity check frame question

  • From: Stephen Sprunk
  • Date: Thu Aug 22 10:08:50 2002

Thus spake <Brennan_Murphy@NAI.com>
> I have a Frame connection between two sites, A and B. If the router
> crashes at B, wouldn't A still see the DLCI for
> B?  Is there any scenario where this wouldn't be the case?  If
> B gets blown off the map, shouldnt A's frame interface be
> in at least an up/down scenario?

In theory, when the remote LMI goes down, or any part of the PVC internal to the
carrier goes down, the local LMI should go INACTIVE.  In practice, this is
unreliable at best; for some carriers, you will always get ACTIVE status no
matter what.

ATM has a similar feature/problem with ILMI.  The only solution is to ignore the
carrier and do it yourself end-to-end (gosh, where have we heard that before?).

End-to-End Keepalives for FR:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/wan_r/wr
dfrely.htm#xtocid18

OAM Loopback for ATM:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/wan_r/wro
ampvc.htm#xtocid0

> If the DLCI disappeared, doesn't that suggest that someone
> deleted the PVC?

Distinguish between INACTIVE and DELETED; those represent very different things
in LMI.

S





Discussion Communities


About Merit | Services | Network | Resources & Support | Network Research
News | Events | Contact | Site Map | Merit Network Home


Merit Network, Inc.