CAM and TCAM

Answered Question
Jul 8th, 2010

what is different between CAM and TCAM table? and both of defult size in switch?

I have this problem too.
0 votes
Correct Answer by Ganesh Hariharan about 6 years 5 months ago
what is different between CAM and TCAM table? and both of defult size in switch?

Hi Abhinay,

CAM table is a special type of memory used by Cisco switches, in the case of ordinary RAM the IOS uses a memory address to get the data

stored at this memory location, while with CAM the IOS does the inverse, it uses the data and the CAM returns the address where the data is stored, also the CAM is considered to be faster than the RAM since the CAM searches the entire memory in one operation.The problem with CAM is that it can only do exact matches on ones and zeros (binary CAMs), and here TCAM (Ternary CAM) comes, since it can match a third state which is any, this makes TCAM a very important component of Cisco layer 3 switches and modern routers, since they can store their routing table in the TCAMs, allowing for very fast lookups, which is considerably better than routing tables stored in ordinary RAM.


Hope to Help !!

Ganesh.H

Remember to rate the helpful post

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4.5 (2 ratings)
Loading.
Correct Answer
Ganesh Hariharan Thu, 07/08/2010 - 21:58
what is different between CAM and TCAM table? and both of defult size in switch?

Hi Abhinay,

CAM table is a special type of memory used by Cisco switches, in the case of ordinary RAM the IOS uses a memory address to get the data

stored at this memory location, while with CAM the IOS does the inverse, it uses the data and the CAM returns the address where the data is stored, also the CAM is considered to be faster than the RAM since the CAM searches the entire memory in one operation.The problem with CAM is that it can only do exact matches on ones and zeros (binary CAMs), and here TCAM (Ternary CAM) comes, since it can match a third state which is any, this makes TCAM a very important component of Cisco layer 3 switches and modern routers, since they can store their routing table in the TCAMs, allowing for very fast lookups, which is considerably better than routing tables stored in ordinary RAM.


Hope to Help !!

Ganesh.H

Remember to rate the helpful post

abhi-adte Fri, 07/09/2010 - 00:48

Hi Ganesh,

Thanks yar I was just confused but now I clear the problem...    

Actions

This Discussion