EPM and NAT with Cisco SPA5xx phones

I have recently purchased the EPM module. Everything seems to work fine except it is not toggling NAT to on in the phone config. These are Cisco SPA 5xx phones. What am I missing? Thanks!

You’ll need to do this in the basefile editor.

Yea I was hoping to avoid that. I wondered why OSS does this and the paid EPM does not. I think it might be because paid EPM drops the register time down to 60secs to essentially do the same thing.

This is what I plan on adding to my base config.

NAT_Mapping_Enable_1_ ua=“na”>yes</NAT_Mapping_Enable_1_
NAT_Keep_Alive_Enable_1_ ua=“na”>yes</NAT_Keep_Alive_Enable_1_

I reckon I spoke with you on IRC. There’s no need for these settings. Fix your network.

I know what you are saying but that’s your perspective.

The way that the OSS EPM module handled the NAT session timeout was to use those settings. This worked in all the situations I had a sonicwall (which has a 30sec timeout by default for UDP sessions) because it used 15sec for a keep-alive timer. The commercial module seems to forego that and get the job done by registering every 60secs.

Now in this case I had access to the firewall (in many cases I do not) and changing the UDP session timeout to 90secs seems to have solved it.

But I can tell you I have several installs using the NAT settings on the phone and they work just fine. The first time I have encountered this was using the commercial EPM. Now I am not complaining about it, it just so happens it caused me an issue because it handles NAT timeouts in a different way.

So hopefully all this might help someone else out whom may run into the same thing using commercial EPM with Cisco SPA5xx phones who might be behind a Sonicwall firewall.

Those NAT settings in the Cisco SPA phones and ATAs is to allow the device to keep the NAT open for the device. This is for when there are NAT issues or other poor network configuration that doesn’t handle the NAT properly.

Yes, you can use these settings but really they aren’t settings that need to be changed. I run SPA 3XX, 5XX, 112s and 8000’s at numerous locations and I rarely have to use those settings in the phones/devices. So yes, this is his perspective but I also said to fix your network as did others in IRC when this was discuss.

In fact I have an SPA508 that I have connected right now with a 1 hour re-register and both those settings set to “No”, not a single issue with the phone going UNREACHABLE or receiving/making calls. It’s a test extension so it sits unused for days and always works.

I just explained how it is used so yes I understand what it is for. My entire point is that in some cases it is preferred or required to not make changes to the network. Using these settings allows you to get around the network situations quite easily.