All things related to multicast

["Kelly, Vaughn [NCSUS Non J&J]" <>]

Title: RE: Multicast traffic causes unicast drops in cisco 15454 SONET mux?

That was the case a couple years ago, but if I'm not mistaken, Cisco's E1000
linecards (released about 1 1/2 years ago) resolved that issue.  It may also
be of some benefit to upgrade the code on your ONS chassis if at all possible.  The problem with tunneling is that it's going to give you decreased performance and add to the overhead on your L3 devices.

Vaughn Kelly | Johnson & Johnson NCS | Advanced Technologies Research |
-----Original Message-----
From: [] On Behalf Of
Sent: Wednesday, March 24, 2004 5:46 PM
To: ; Peter Gutierrez
Subject: Re: Multicast traffic causes unicast drops in cisco 15454 SONET mux?

Peter, I've seen this problem before. It came up a few years ago when I was
building out a large service provider network. If I remember correctly, the
solution was a software/line card upgrade. This a line card limitation. Best
way to handle it is to keep multicast traffic to a minimum, try tunneling
multicast with GRE and configure routing protocols to use unicast updates.
The link below should give you some more information.

http://www.cisco.com/warp/public/770/fn13171.shtml

Artie

----- Original Message -----
From: "Peter Gutierrez" <>
To: <>
Sent: Wednesday, March 24, 2004 10:15 AM
Subject: Multicast traffic causes unicast drops in cisco 15454 SONET mux?

> My Internet 2 traffic is using a new circuit provisioned by a provider
> that I Wil^H^H on't Tel the name of here, who is claiming that some
> small but persistent unicast packet loss is caused by a problem
> handling PIM traffic. We connect to what they call a Cerent box, which
> I assume is the cisco (that borg'ed Cerent) ONS 15454 SONET mux, via
> GigEthernet, that is carried around the SONET ring in an OC12 slice,
> average traffic rate 100Mbs, and hands off GigE to a cicso 6509 router.
> Does anyone else have the same transport system, with problems caused
> by multicast traffic?
>
> --
> Peter Gutierrez  OIT/Network Services  U. Massachusetts Amherst
> Voice: 413 545 1606   Fax: 413 545 3203   
> Opinions?  "Ain't nobody's business but my own" - Irving Taylor