[6652] in North American Network Operators' Group
Re: Film at 11:00
daemon@ATHENA.MIT.EDU (Tony Li)
Tue Dec 31 16:08:08 1996
Date: Tue, 31 Dec 1996 12:52:43 -0800 (PST)
From: Tony Li <tli@jnx.com>
To: alex@relcom.EU.net
CC: pferguso@cisco.com, tli@jnx.com, nanog@merit.edu
In-reply-to: <ACbrEoo4vO@virgin.relcom.EU.net> (alex@relcom.EU.net)
Hmm, it's not news for us. 45K can hold core routing only as
inter-back-bone router, not more.
But why, why this crasy CISCO could not predict future when
they designed 45K routers? It was not difficult for them
develop this box to cary 64 or 128MB RAM.
> Looks like the 45k mark was reached:
>
> Folks with 7000's and SSE's should start monitoring their memory
> utilization via "show sse summary".
There's a couple of comments here:
First, 45k is not the limit. More like 60k. You'll pardon me for being
cautious.
The limitation is not DRAM. It's the 64k words of SRAM that the SSE uses
for its high speed forwarding table. You don't want to pay for 64Mbytes of
SRAM. ;-)
When cisco's engineers designed the SSE, we knew very well what was
happening. We expected to be given the opportunity to produce subsequent
hardware which implemented the SSE in an ASIC. If, by that time, CIDR
hadn't killed off the exponential growth, we would have expanded the
address space. Unfortunately, cisco management decided that the SSE ASIC
should not be implemented (a mistake which, to my knowledge, cisco has not
corrected). Thus, the 7500 exists without an SSE.
Tony
