Thursday, 10 July 2014

NEC Aspire Slow Dialling SIP Trunks

Dialling a number on a SIP trunk would result in a wait of 10 seconds from the last number key press until the Aspire sent the SIP INVITE packet.  This was really annoying and not really acceptable as the same delay did not seem to occur on an ISDN trunk.

As a workaround, if a # was entered after the last digit it forced an immediate dial and bypassed the wait timer.

A more permanent solution was to adjust programming option 21-01-03 External Call Inter-digit Time to 5 from 10.  This halves the time out until dialling occurs but set any lower could cause issues with users not being able to dial digits fast enough.

Friday, 4 July 2014

Recover Cisco 7970 IP Phone From Failed Factory Reset

I tried to upgrade a 7970 to 9.3 SCCP firmware and it wouldn't connect to my CME so I performed a factory reset using this method and the phone appeared to be bricked.

After power up it was just showing a blank screen followed by green lit headset light and cycling green line buttons.  What I didn't know was that the factory reset actually removes the firmware from the phone and it now needed to find it again.

Some investigation showed that it was requesting an IP form DHCP and was requesting the file term70.default.loads from the option 150 TFTP server address.

Trying many different firmware versions and different TFTP servers it would successfully get the term70.default.loads but not do anything with it.  Eventually I went all the way back down to firmware version 8.3 which I sourced from here.

With version 8.3 loaded on the tftp server the phone successfully read the term70.default.loads and continue to download the other binaries required although I had to rename the jar70sccp... file to Jar70sccp... with a capital J.

When reconnected to CME it still fails to load firmware version 9.3 with the message "Load Authentication Failed".  I suspect that the signing certificate in 8.3 is unable to authenticate the load of 9.3 given that 8.3 was released back in 2007 and it's probably expired.