SIP registrations failing for 2 phones
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So I installed a new ERL, assigned it a public static IP & Gateway and the internet is working. However, I am still having the same issue with only about 3 of the 6 devices. (where they keep being marked as unreachable.)
The Comcast "Gateway" has an option to go into Bridged Mode. This is what I was planning on doing, in an attempt to completely bypass the comcast box, and eliminate any chances of double NATing, or some other issue messing with SIP. I called Comcast and they tell me that enabling Bridged Mode will not work with a static IP address. So I tried switching to bridged mode anyway, and sure enough, it didn't work. No internet access was possible. Switching back to "normal" mode solves the internet issue, but I still have have the issues with the phones being marked as unreachable.
This really feels like some sort of double NAT issue, or something else on the Comcast gateway causing the NAT holes to close. It's almost like it cannot handle more than 3 simultaneous SIP connections. The problems are not with the phones, as I've tested them at other locations outside of this location and they have no issues whatsoever. The problems are not specific to specific phones either. There are always problems with 3 of the 6 devices.
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@fuznutz04 said in SIP registrations failing for 2 phones:
This really feels like some sort of double NAT issue,
An unreasonable assumption. The likelihood is that it is the expected issue with the Comcast router, the router which you were intending to replace but did not so it is still in place causing the issue. The double NAT doesn't help, but we know isn't the issue as the issue existed before that.
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Basically what Comcast is telling you is that they don't have any business offering.
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@scottalanmiller said in SIP registrations failing for 2 phones:
Basically what Comcast is telling you is that they don't have any business offering.
Which is a joke, because it is their "business class" service. There has to be a way to bypass this. I know of others with Comcast business gateways that operate fine. I was reading many forums this evening and some people are saying that certain models of the business gateway have issues with VoIP and that I should request a new/different model from comcast.
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@fuznutz04 said in SIP registrations failing for 2 phones:
@scottalanmiller said in SIP registrations failing for 2 phones:
Basically what Comcast is telling you is that they don't have any business offering.
Which is a joke, because it is their "business class" service. There has to be a way to bypass this. I know of others with Comcast business gateways that operate fine. I was reading many forums this evening and some people are saying that certain models of the business gateway have issues with VoIP and that I should request a new/different model from comcast.
Comcast specifically requires their router be used for static IP customers. You can bring your own modem only with DHCP service from them.
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@JaredBusch said in SIP registrations failing for 2 phones:
@fuznutz04 said in SIP registrations failing for 2 phones:
@scottalanmiller said in SIP registrations failing for 2 phones:
Basically what Comcast is telling you is that they don't have any business offering.
Which is a joke, because it is their "business class" service. There has to be a way to bypass this. I know of others with Comcast business gateways that operate fine. I was reading many forums this evening and some people are saying that certain models of the business gateway have issues with VoIP and that I should request a new/different model from comcast.
Comcast specifically requires their router be used for static IP customers. You can bring your own modem only with DHCP service from them.
I wonder, how often do they change their DHCP provided addresses? Cox residential, in my area, rarely changes IPs. I had the same IP for over a year before.
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What Jared said. We have a location on Comcast with a static IP. Comcast was supposed to send us a modem only, but send a modem/router instead. Even though we worked with Comcast support to bridge their piece of crap and could get our router connected, it never ever worked. FINALLY (after I think 3 maybe 4 support calls and truck rolls) thelast truck tech replaced it with an arris modem only and we got it to work. You may just have to call them and be as persistent as possible.
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Is static really needed? How often is static needed for business customers today?
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@fuznutz04 said in SIP registrations failing for 2 phones:
I have a client who has a comcast business connection (cable 50/20), with Comcast's cable modem acting as the firewall/router for the internal network (7 people). Their PBX is FreePBX, hosted offsite as a VPS. All of their phones are able to make outbound calls. 2 of their phones, keep losing registration with the server, so when calls come in to the incoming queue/ring group, those 2 phones do not ring, because FreePBX has marked them as unreachable. Has anyone had any issues similar to this? I've already factory reset the phones, and removed and re-added the problem extensions to rule out a misconfiguration. Still experiencing the same issues where the phones register, then unregister.
Maybe it's a hardware issue. Try a different phone, Network Cable, Switch port etc.
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So finally go this working earlier today. At one point, as I was scratching my head, everything started working. The only thing that I changed today on the Comcast gateway was a setting that was under "True Static IP Port Management."
The option to "disable all rules and allow all inbound traffic through."
I checked this box, and nothing changed. Then without doing anything else on the Comcast box, or the ERL, about 20 minutes later, all the phones started functioning properly.
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@fuznutz04 said in SIP registrations failing for 2 phones:
So finally go this working earlier today. At one point, as I was scratching my head, everything started working. The only thing that I changed today on the Comcast gateway was a setting that was under "True Static IP Port Management."
The option to "disable all rules and allow all inbound traffic through."
I checked this box, and nothing changed. Then without doing anything else on the Comcast box, or the ERL, about 20 minutes later, all the phones started functioning properly.
If you had rebooted all the gear, it would have likely started working immediately.
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True. I didn't because there were people on the phone at the time.
Big lessons learned here with Comcast equipment. Hopefully I don't run into this again but if I do, lots of notes were taken.
Thanks everyone for helping to think through this one with me.
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their bridge mode isn't a true bridge either. just FYI
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@hubtechagain said in SIP registrations failing for 2 phones:
their bridge mode isn't a true bridge either. just FYI
Well the bridge mode they normally do is not.
Complain the right way and they CAN set them to true bridged mode if they are not static. Have not had to force the issue with them for a static assigned system yet.
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@hubtechagain said in SIP registrations failing for 2 phones:
their bridge mode isn't a true bridge either. just FYI
Right. I was reading up on that a bit. People seem to call it a "pseudo bridge mode."
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@fuznutz04 said in SIP registrations failing for 2 phones:
@hubtechagain said in SIP registrations failing for 2 phones:
their bridge mode isn't a true bridge either. just FYI
Right. I was reading up on that a bit. People seem to call it a "pseudo bridge mode."
That's why they call it "bridge mode" rather than bridging.
