A software defect has been found in Cisco IOS Release 12.3(7)T when using Cisco CallManager Express or Survivable Remote Site Telephony (SRST) and Session Initiation Protocol (SIP) destinations. In particular, if a Cisco IP Phone is configured to call forward to a SIP destination, like Cisco Unity Express (CUE), the router could experience a bus error, causing the router to crash and reload.
The vulnerability has been reported in version 12.3(7)T image only. This defect is scheduled to be fixed in the 12.3(7)T1 image, to be posted to CCO in early April 2004.
For a workaround for this issue, Cisco IOS translation rules can be used to route incoming 10-digit, E.164 called numbers to abbreviated extensions. This example routes incoming calls to E.164 number 4085551000 to 4-digit extension 1000:
voice translation-rule 1
..rule 1 /4085551000/ /1000/
voice translation-profile pstn-incoming
..translate called 1
dial-peer voice 1 pots
..translation-profile incoming pstn-incoming
..incoming called-number 4085551000
Customers using a Network Module Cisco Unity Express (NM-CUE) can continue to use version 12.3(4)T with CUE version 1.1 software. Customers using the AIM-CUE module are required to use version 12.3(7)T. Therefore, you must use the translation rules.