3640 interface conflict

[admin_2]

I have a 3640 router with 4 port serial interface and 2 port fastethernet card. I'm trying to add NM-1HSSI card to the router with external CSU Adtran t3su 300. When I have all 3 cards in the router I cannot run ping command with datagram size 1500 to the looped Adtran. When Hssi card is by itself I can ping datagram 1500 and bigger.

Can this router support this configuration ?

Any help would be greatly appreciated.

[vmoopeung]

This can be because of the problem of insufficent DRAM, which is the IOS version you are running or can be because of a bug CSCdx38690. This symptom is observed on an HSSI network module that is installed on a Cisco 3600 router that is running Cisco IOS Release 12.2(10) or Release 12.2(10.3)T. These issues are fixed in Cisco IOS 12.2(12) and later. May be you have to upgrade your memory while upgrading .