Folks,

I've recently purchased a Nortel 1535 SIP phone and have not had any success in using it through my Mikrotik based network.

Has anyone had any experience with SIP devices and in particular whether NAT is a problem or what firewall ports need to be opened and any other special configurations needed?

I've tried and failed to get the device to register with sipgate and with sip2sip.info.

In particular, I should like to hear from anyone who has any experience with the Nortel 1535.

Cheers

Ian

I'm not failure with the phone you specify but I use a different brand. I use the sip phones with the Mikrotik units with no issues and do not modify the configuration of the Mikrotik from my basic configuration of Station Receive and nat routing behind that.

The issues I've seen with sip phones have been related to the sip phone and voip pbx settings. One thing to avoid is having the phone deal with nat. When I setup a voip phone I have nat set to no and keep-alive set to yes. The keep alive keeps the ports open to the pbx server.

On my pbx server I have a setting that says nat=yes or no. This is what I have set to yes. You do not want server and sip adapter both set to nat=yes. They won't see each other.

I am using Asterisk pbx with Sipura (now Linksys/Cisco) ata's.

Hope this helps,
Michael

On ours we also had to reduce the keepalive times in SIP to 30 seconds. I forget why, but I think it was or is because the router connection tracking information isn't kept for very long for UDP packets (which SIP uses, and which can be an issue if you are packet forwarding or NATing).

Also, echoing previous comments, SIP and NAT can be a nightmare. It also helps (perhaps is necessary) if your NAT device knows about SIP (which I think RouterOS does, at least for the last couple of years or so, possibly longer).

I think the relevant ports are 5060 and 5061.

If something is screwed up (especially in NAT, or connection tracking) you may see issues such as you can make calls, but not receive them or vs versa; or the phone appears to be registered, but doesn't work otherwise.

Thanks for these helpful comments. Thus far I have had problems with registration, rather more fundamental than not being able to receive and/or make calls.

Sipgate has a stun service which can be enabled or disabled on the phone - I get the same result either way. Also, numeric address or fqdn makes no difference either.

One thing I have read is that these phones might be better with numeric only passwords but have yet to test that.

The phone works with WiFi no problem, save that it does not work with aes so I have created a Virtual AP with tkip only and limited to one client just for the phone and linked to the router's bridge so within the usual addressing range.

The phone can see the local ntp server (on the mikrotik) and can browse (poorly but what can you do with a 200 pixel screen) the web. It is communicating and that is for sure. Sadly not with sipgate.

Regards

Ian

no problems with the Mikrotik and SIP. Works out of the box, no need for NAT or anything like it. You should have your ADSL modem in pure bridge mode, and use PPPoE from Mikrotik.

Have several phones behind multiple locations w/ MT. works great. Even the VM server itself is firewalled w/ proxyarp behind a MT. Keepalives are set at 60seconds. Polycom phones (Which I hear are known for not being NAT friendly.)

I think I need more help - I am now confused.

The good news seems to be that I am now seeing a better error message from the phone than 'Registration Failed' which was all I was getting before. I am now getting '504 Server Timeout'.

I have tried varying the NAT timeout on the phone - between 30s (min) and 90s there is no difference in result. There is also a 'registration timeout' which I don't think I need to worry about until I have obtained a registration. It is currently set to 60 (unitless).

I have tried to set up port forwarding to the SIP Phone but I think it is only working one way. The parameters on the phone are different to those described anywhere else.

What is clear to me is that STUN doesn't help - I get a lot of connection attempts with STUN enabled but with it disabled everything is or appears to be happening on port 5060 udp.

Any further thoughts?

Ian

Its working. I don't know quite what I did but I now have a Nortel 1535 SIP phone working on my MT network - it works with the external sipgate provider too. I have documented the settings if anyone wants to see what they were.

Ian

Helo ibeeby, I am interested. Can you post or send those settings please? thanks