FXS Lockup

[knowlerp]

We have a 3640 Router with PRI ISDN for incoming calls and an FXS card with a fax attached.

Incoming calls are matched to the dial peer and route to the fax ok.

However when the calling party clears down the FXS stays offhook

The only way I can reset this is to remove the voice-port config from the router,reload the router and then put the voice-port config.

This happens on every call to the fax - any ideas ?

I have compare configs with sites that work fine and can see no differences

[jcraven]

I've been fighting a very similar problem with different hardware. The router is a 2851, but otherwise it is exactly like you are describing. I've replaced FXS cards, etc during troubleshooting.

When it happens, I see a single call leg belonging to the FXS port and fax digits that stays up (using show call active voice brief). The only way to kill the call is to reboot the router.

As of the last few weeks, I might just have it licked. HEre are a few things that I hope help you:

1. make sure you are only using 2-wire cables versus 4-wire on this FXS port and any other ports on the same card.

2. Try the global command ' fax send max-speed 9600'. To me, it should not apply to this problem, but it seems it may have helped me.

3. under the FXS card, try setting the timeouts ringing to high number, say 120.

Hope that helps,

Jerry Craven

[jcraven]

To anyone else who has the misfortune of fighting this one, this is a bug. I only know of it affecting 2800 series routers, but I imagine there could be others. From the 3rd TAC case I had on the bug over the last 3 months:

"CSCeh39561

Internally found severe defect: Resolved (R) back out changes in the FAX stuck in TSP_DISC_PROG_IND_REL state

This DDTS is internal, so you won't be able to see it using our CCO Bug Toolkit.

2) As of today, this bug is integrated in the following images:

12.4(1.2)

12.3(14.10)..."

Cheers,

Jerry