modify "Expires" value for SUBSCRIBE-NOTIFY

[crossroads]

1. Brekeke Product Name and version: PBX2.0

2. Java version:1.5

3. OS type and the version: Server 2003

4. UA (phone), gateway or other hardware/software involved: Cisco 3640

5. Select your network pattern from http://www.brekeke-sip.com/bbs/network/ ... terns.html :

6. Your problem:

I have few Phone device with multiple lines registered to the PBX with Voice mails. Our devices do MWI through SUBSCRIBE-NOTIFY. While sniffing the network, found that the NOTIFY is set to expire every 60 seconds and hence putting too much traffic from one single device on the n/w.

I would like to know how to modify the Expires to to some value in NOTIFY.

Thanks