Yealink subscribe request - no response by 3CX

[workspace]

Using a brand new Yealink T46S phone I can see the Subscribe multicast with WireShark:
47 276.862179 10.xxx.yyy.zzz 224.0.1.75 SIP 565 Request: SUBSCRIBE sip:[email protected] |
and I can see the same packet received in the dump.pcap file on the 3CX server (15.5, debian, new install):
307 56.584635 10.xxx.yyy.zzz 224.0.1.75 SIP 565 Request: SUBSCRIBE sip:[email protected] |
I am supposed to see a 202 response from 3CX (http://support.yealink.com/faq/faqInfo?id=540) but I see no response at all.

I am pretty much a noob at this stuff (but not to networking) so I might be missing something simple. I have checked to make sure the IP Blacklist is empty. Both the phone and 3CX are fully up to date.

Where should I look for my next step at what might be wrong?

Thanks,
-g

 

[workspace]

I should mention that I have a manually provisioned a different Yealink T46S phone which is working just fine. It is able to make and receive calls with no issue at all. I'm trying to figure out why my factory "new" phone isn't getting to first base.

 

[workspace]

OK, I just made some progress. I googled about 3CX and multicast and found this link: "V15.5: PnP Multicast Debug" and it told me to issue netstat-g on an SSH console and look for sip.mcast.net.

This was not found. On my system the results show:

root@xxxxxxxx:~# netstat -g
IPv6/IPv4 Group Memberships
Interface RefCnt Group
--------------- ------ ---------------------
lo 1 all-systems.mcast.net
eno1 1 all-systems.mcast.net
lo 1 ip6-allnodes
lo 1 ff01::1
eno1 1 ff02::1:ff65:8b6
eno1 1 ip6-allnodes
eno1 1 ff01::1​

(is there a code tag or something I can use?)

I wondered how to add the item and via el google found this entry "adding sip.mcast.net to multicast group debian stretch" in this forum and it mentioned that simply running the firewall checker would add it back.

So I did, and it did:

root@xxxxxxxx:~# netstat -g
IPv6/IPv4 Group Memberships
Interface RefCnt Group
--------------- ------ ---------------------
lo 1 all-systems.mcast.net
eno1 1 sip.mcast.net
eno1 1 all-systems.mcast.net
lo 1 ip6-allnodes
lo 1 ff01::1
eno1 1 ff02::1:ff65:8b6
eno1 1 ip6-allnodes
eno1 1 ff01::1​

And, I just unplugged and re-plugged that T46S that won't show up and Presto! I got a reply from the 3CX server

8574 80.498371 10.xxx.yyy.aaa 10.xxx.yyy.zzz SIP 350 Status: 500 OK |​

I am a happy person just now.

Continuing on...
Now, this is a vanilla install created just a few days ago from the latest ISO. I have restarted the 3CX server many times in the last few days. So I rebooted it again just now and ...

It's missing again:

root@xxxxxxxx:~# netstat -g
IPv6/IPv4 Group Memberships
Interface RefCnt Group
--------------- ------ ---------------------
lo 1 all-systems.mcast.net
eno1 1 all-systems.mcast.net
lo 1 ip6-allnodes
lo 1 ff01::1
eno1 1 ff02::1:ff65:8b6
eno1 1 ip6-allnodes
eno1 1 ff01::1
root@OCT3CX-D1:~#
root@OCT3CX-D1:~#​

So, the sip.mcast.net disappears after the server as a whole is rebooted. NickD_3CX in the post above mentioned that this is something that the "3CX support team can and will look into." so I'm hoping I can get some traction even though I'm a rank beginner working through my first commercial install as a reseller.

I'm feeling progress has been made, now to get that missing sip.mcast.net entry to stick!

-g

 

[eddv123]

Just to note I had exactly the same issue once before and the firewall checker was the fix.

I would like to know the reason why as this was not the case with earlier versions of 3CX.

 

[workspace]

Two more things. The 3CX phone is Pro Annual 15.5.15502.6 so this is the absolute latest version. I downloaded it early last week. Second, I installed a PBXExpress on Google and I did not have the problem there. That one is using my NFR license and is the same 15502.6 build. Once installed, I accessed the SSH console and did the netstat -g. It was there. I then restarted that VM Instance and checked again. It was still there.

I'm installed using an Intel NUC if that makes any difference and I installed it from a downloaded debian ISO.

 

[eddv123]

NUC should make no difference at all.

Just to confirm multicast stops at router/firewall/border devices so if you are using a cloud PBX you won't get pnp functionality.

Using the 3CX SBC is the only way to gain pnp-like behaviour with u fully supported/preferred phone brand.

 

[workspace]

I was pretty sure that the NUC shouldn't be a problem. I had used it on a previous install (test about a year ago) and had no problems. Still, something must be different. The PBX Express install was just to do it while I was watching the Intermediate Academy training and I figured I try the netstat -g to see what happened.

It would be nice if there was a debian package for the SBC. I can place it on very small footprint boxes and just stick it in the phone closet.