NO inbound voice when no NAT

[rgmhtt]

My Asterisk box is publicly addressed, behind a firewall.

I have done extensive study with tcpdump on this and can give packet by packet details if needed....

When my * box is behind a Linksys WRT54g running sveasoft, I have voice on incoming calls. When it is behind a generic Linux Netfilters firewall, I get the call but no voice.

Note the 2 firewalls are identically addressed. It is a matter of switching cables to switch firewalls.

First thing I noted in the dumps was with Linksys, the INVITE from Broadvoice contained information to direct the RTP flow to a different Boradvoice server. I am assuming that this is a box tuned for RTP flows, whereas the one we register to is just a proxy box. But with Generic Linux, there is no such information in the INVITE, the RTP flow goes to the Broadvoice proxy SIP server which sends ICMP port not available messages.

Further study determined that although the firewall function was OFF on the Linksys (I still had to configure the * box as the DMZ system), the REGISTER Contact line was getting mangled. :5060 was being added after the IP address. Thus Phone#@sip.foo.com became Phone#@sip.foo.com:5060. Of course * is NOT putting this port information. I then found most of the messages coming from * were mangled in this way.

It almost seems like Broadvoice is dump and expects a NAT?

Anyway it is clear that I have to get * to append the port number itself. I don't want the firewall doing this...

I put nat=yes in my conf sip.conf file section for Broadvoice, but no change.

What is the magic option to get this to work?

[los]

have you tried the externip and localnet options on the sip settings ?

examples below

externip=123.456.789.123 ; your external ip
localnet=192.168.1.0/255.255.255.0 ; your internal range

[rgmhtt]

Originally Posted by los

have you tried the externip and localnet options on the sip settings ?

examples below

externip=123.456.789.123 ; your external ip
localnet=192.168.1.0/255.255.255.0 ; your internal range

Um, my "external" IP address is in my 'localnet':

externip=208.83.67.138
localnet=208.83.67.136/255.255.255.248

Like I said. No NAT. Publicly routable addresses. The firewall has an address on the 208.83.67.136 network (its internal interface) and an address on my 'public' network. But it is really 'just' a router permitting or rejecting packets. No mangling.

Here is what Wireshark shows of the COntact field in the REGISTER

Linksys with mangling:

Contact: <sip:2482910713@208.83.67.138:5060>

Netfilter; just routing:

Contact: <sip:2482910713@208.83.67.138>

So somehow, I have to get Asterisk to add the port number to the Contact.

BTW, for outgoing calls, * still sends a REGISTER with Contact: <sip:2482910713@208.83.67.138>, but Broadvoice in the Sessoin Progress SDP has:

Connection Information (c): IN IP4 147.135.12.247

so when Broadvoice is 'invited' to a call, it figures out the right Connection process from port information elswhere in the INVITE. But if it has to 'invite', it needs the port number as part of the Contact information...

[rgmhtt]

Just got a reply on this problem over on the Asterisk-dev list.

No way to 'patch' around this, so I am looking for another provider that has a similarly priced BYOD and can provide me with a 248 area code number...

"At this point, you have to change the source code.
If there's no port number mentioned in a SIP uri, it means that we default to the default in the RFC, which is 5060. So there's should be no need to add it to the URI and it should not make any difference in an ideal world ;-) "