in my LAN I'm using sipXecs (http://www.sipfoundry.org/) a popular open source PBX.
It is pretty simple and easy to use. I have gateways and phones successfully working with it.
I wanted to use my nokia e51 but unfortunately it aways claim it cannot register. The phone connect to the server via wlan. Phone and server are on the same ip lan perfectly reaching each other. No router, no firewall, no nat.
So I checked the exchange of register messages between the phone and the sever. I couldn't understand myself why the server always responded with an unregister. So I asked for help to the Sipfoundry community.
They analyzed the log and said:
If you examine the REGISTER requests closely, you'll see that they all
have different Call-Id and from-tag values. sipX rejects each REGISTER
request with a 401 and provides an authentication nonce. But in sipX,
the nonces are bound to the Call-Id and from-tag values; they can't be
re-used in different dialogs. (This helps prevent forgeries.)
RFC 3261 section 22.2 states that if a request is rejected for
authentication, the UAC must resend the request, with an incremented
CSeq but the same Call-Id and from-tag. Unfortunately, the Symbian is
violating this rule, so the nonce that it gets in response to one
REGISTER is not usable in the next REGISTER it generates.
You'll have to get Nokia to fix this.
I had the same registration problem with a nokia e90.
Can you investigate if this is this really a bug?
Thanks in advance.