[c-nsp] memory on vip4

[Pete Templin]

Maxim Tuliuk wrote:
> I setup vip4-50 and "128 MBytes CPU SDRAM, 128 MBytes Packet SDRAM", but...
> what is more used: "CPU SDRAM" or "Packet SDRAM" - the main goal is
> full-view, 20-30 costomers with rate-limits/acls, and 100-200Mbit/s
> i.e. 128/128 is enough or not?
> p.s. Can I look at statistics vip memory (like sh contr vip . proc cpu) ?

CPU memory is used to hold a copy of the IOS image for the VIP, and the 
CEF table (let's just assume you're running dCEF).  The specific IOS 
image will dictate how much memory is needed for the VIP's sub-image. 
The number of prefixes in your RIB will then dictate how much additional 
memory is used on the VIP.  On a lab box with very few routes in its 
RIB, memory usage is about 18MB.  On a production box receiving 171,360 
routes from the adjacent route-reflectors, memory usage is about 61MB. 
This will change based on the number of routes in the RIB/FIB, but won't 
care how many BGP neighbors you have, etc.

Packet memory is used to hold packets in transit; low-speed interfaces 
are quite likely to need some buffer room as packets queue up arriving 
from higher-speed interfaces.  QoS features in use and the difference in 
media rates will likely dictate how much memory is used, but should 
normally be managed by the box.

pt