smart serial cards and 3640 routers

[s.muhammadi]

I have a remote site where I have a Cisco 3640 router with following cards:

Slot 1: unused FE, Unused TR, 1 WIN card with active BRI

Slot 2: 2 FE with one FE used, 2 2 port WIC with 1 serial used (Frame Relay T1).

When I add another Frame T1 to a smart serial port in slot 1 I see very high latency and packet loss. Note that router has 96M of memory and CPU is registering very small utilization. Replacing cable, port and CSU/DSU did not help. When I connect the same T1 to a separate router I don not see any latency and packet loss. Also, I installed a 4 port serial card (NM-4T) in slot 3 and connect the second T1 to it and I don't see any latency or packet loss problem.

First I thought the problem may be in smart serial card, but I am seeing similar result for two other sites. Looks like to me that there is some limitations with Smart serial card in one slot on 3640 router, I checked Cisco web site but could not find any such limitations? Can anyone give me any idea why I am seeing this problem?

Any comments or ideas will be appreciated.

[thisisshanky]

According to this document, it should support 2 ports at 4 Mbps each on a NM with FE interfaces.

http://www.cisco.com/en/US/products/hw/modules/ps3129/products_tech_note09186a00800b0858.shtml

Try adding another wic-2t (if youhave one) and see if that helps!!

[s.muhammadi]

Thanks for your reply. This document suggest 4M per port and I have only 1.5M per port. I am going to try 1 port WIC card annd will see if it helps though I would like to know why I am seeing problems with 2 port WIC (WIC-2T)

Shakir Muhammadi