Cisco Vip Cards.

Steve Martin steve at
Wed Dec 10 21:23:06 UTC 1997

Hi Randy,

We have seen situations under heavy load where a VIP2-40 with an OC3 
running at 80% and a Fast Ethernet PA running at 50% have resulted in 
severe packet loss and latency. After addressing this with our Cisco reps 
(including the Product Manager and Product Engineer for the 7513/VIP 
family) they acknowledged the problem and stated:

"We do not recommend putting any other PA into a VIP2-40 if an OC3-PA is 
already installed. We have seen adverse performance, in the way of latency 
and packet loss, resulting from such a configuration. Customer's choosing 
to do so, do so at their own risk".

Whether this is a company wide, advertised position at Cisco is unknown.

During a recent, major launch, our Fast-E PA providing uplink connectivity 
to our download servers was located on the same VIP as one of our major NAP 
OC3 PA's. At 80% utilization on the Fast E and 50% on the OC3 we started 
seeing packet loss and increased latency. When the OC3 gets real busy, the 
SARing work consumes most of the VIP's resources. Additional taxation from 
other media interfaces pushes the VIP over the edge and it starts dropping 
packets and delaying throughput.

It was such a problem for us that Cisco offered special pricing bundle's 
for us until the VIP2-50 could come out and handle the aggreagate loads 


-----Original Message-----
From:	Randy Bush [SMTP:randy at]
Sent:	Wednesday, December 10, 1997 12:37 PM
To:	Steve Martin
Cc:	north american nominated origin of gossip
Subject:	RE: Cisco Vip Cards.

> Cisco will not support multiple PA's within a VIP2-40.

I do not believe this statement to be true.


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