Polycom & Sofaware & Asterisk


Just thought to post our experiences trying to get a Polycom Soundpoint 450 working through a Sofaware to an endpoint doing SIP natting.

As mentioned above our situation was such. We use Asterisk as our PBX and have SIP natted through the corporate firewalls. A remote user has a Polycom 450, and we purchased for him a Safe@Office 500.

It was a bit of a struggle to get it working, but once we finished it the setup is working like a champ for the user.

The highlight points for anyone attempting anything similar are:

  1. If you want to provision the phone using boot options(which I highly suggest), none of the DHCP options in the 500W match option 66 from DHCP. that being said we programmed the Polycom to use a different option. The Avays IP Phone option is 176, so you can configure the phone to use that boot option instead of the default 66. We had to capture the traffic using all three options to find out what they were exactly. Wireshark gave us the exact details needed. Once we knew that you can simply enter the IP of your ftp server used for provisioning.

  2. If you are using provisioning like above, definitely look at the NAT options available in the Polycom config files. The latest document I have is: polycom.com/global/documents … _2_eng.pdf. Check out page A - 151 for the natting options. We ended up not needing the nat.ip option because the sofaware did pretty good natting already. However we used the keepalive, signal and media port options:

  3. The final touch was kind of surprising, the smartdefense options caused more problems, another post on sofaware.infopop.cc, mentions disabling both options which worked perfectly, using the console we turned the smart defense option off like so:

set smartdefense ai voip sip alg disable enforce-rfc disabled

It seems that this option turned on caused the connection to time out roughly every 65 seconds. At first this was stumping us as we figured it was a UDP timeout issue on the firewalls, but we dug up the post suggesting to turn it off.

All in all this setup is definitely possible, and seems to work quite well for us. Just thought to post our adventures in case others need to do something similar.


Darrin Henshaw