Connect AS400 via CIP Attached Router/Frame Relay/Remote 1720 w serial

[2r.ross]

Have connected AS/400 from old T1 Channel at 56Kb and moved to serial cable on Cisco 1720 Router. Shows UP/UP and Strnm Sent. IBM says AS400 see poll and ack's but apparently ack never gets to VTAm on Host. Help???

This is driving us nuts. IBM noted we are either polling too fast or ???

Any help/suggestion would be appreciated. WE have other SDLC systems operating such as ATM Machines, and controllers, and some other AS/400's, but this one is not cooperating. What am I missing. Any points will be greatly appreciated. Debugging info would be appreciated....

[dixho]

Is the AS/400 on a point to point or multi-drop line? There is a known issue a while back on AS/400 and Cisco routers on multi-drop line. AS/400 has a different behavor on idle characters than FEP. Please find out if the AS/400 has PTF# MF10030 applied or not.

Regardless if the patch is applied or not, please configure "idle-character mark" and "sdlc k1" on the sdlc interface. The commands should fix the issue.

If not, please run debug sdlc packet and AS/400 communication trace at the same time. If you have more than one SDLC interfaces or more than 1 SDLC addresses on the interface, please shut down all other interfaces.