Phones not registering with certain routers

[inteq]

Hello

I have some problem getting Cisco SPA512G phones to connect to our 3CX server over the internet.
To make the long story short, it seems that some routers just don't work in a VoIP environment.
The phones do not register at all with them, while the same phones with the same settings are registering just fine with other routers.
So far I have tested routers from TP-LINK - TL-ER5210 and NETGEAR - FVS338. Both routers don't allow somehow the phones to register over the internet, behind NAT. With the NETGEAR I can only register one phone at a time, but not more than one.
With other routers from Asus or Zyxel, all phones are registering just fine.
I tried various settings, disabled ALG where I could. No luck.
The only way I could get one phone to register is by setting it up in DMZ (which in the long run won't cut it)
Of course, the routers in question are allowing outbound connections.

Besides just changing the routers I am running out of ideas.
Anyone stumbled upon this kind of problem and was able to solve it somehow?

Later edit, adding other router models as I come across them, so others can stay away from such models in a voip environment.

Not working at all or partially:
TP-LINK - TL-ER5210
NETGEAR - FVS338
D-LINK DIR 615 (300)

 

[lneblett]

Change the SIP port on the phones such that not all read 5060. You did not mention if you followed the guides on how to remote extensions as found in the blog, if the 3CX instance is running STUN or if with a fixed IP. Finally, if a PC is available at the remote site, you can always try the SIP Proxy manager to tunnel through the confusion.

 

[inteq]

Hello Ineblett.

As you can see, the phones configuration is OK, otherwise it would not work at all.
In my situation, the phones are not registering with two routers but registering just fine with others..
Using that proxy is out of the question.
Will just change the routers.

 

[jpillow]

For instances like those the best routewould be to just use the SPM why is it out of the question in this route? If so you may have to use whateber router you know whill work.

 

[lneblett]

Sorry, but your question was has anyone had this issue and was able to solve it. I gave you some solutions that I have indeed come across as solutions in some situations. If a router change is more to your liking as it works with no change to phone settings, then by all means...go for it.

 

[3CXfoxhallsolutions]

Hi Inteq
I've had the same issues with Linksys and Cisco SPA phone models, and agree with the comments above regarding 'local SIP ports'. The Cisco phones have ascending SIP port addresses on each extension; Ext1 = 5060, Ext2 = 5061, Ext3 = 5062 etc. Each phone is the same and therefore, you get a situation where the router at the remote site is servicing multiple requests by different IP addresses for communication over the same port number ... While this should not be a problem! it just seems to cause registration issues.
I now tend to use Yealink phones - but have recently cured an ongoing Linksys SPA remote site issue, by emulating the settings that are suggested in the provisioning settings of a Yealink remote (STUN) extension profile i.e. set each phone with a different local SIP port, and also with different RTP port range - then set corresponding open ports on that remote router to support the SIP port and RTP port range to EACH phone ... e.g. 1st phone - Ext1 5065 ... RTP ports 14000 to 14009, 2nd phone Ext1 5066 ... RTP ports 14010 to 14019 etc.
[SIP port is set on the 'EXT1' page of course, and RTP range is set on the 'SIP' page ...]
Have a look at this video ... well worth the time ...
http://www.3cx.com/blog/advanced-training/configuring-remote-extensions/

Once I had done this on the Linksys SPA phones at the remote site - my support phone stopped ringing! Yay!!
I use Draytek routers by the way ...

 

[inteq]

Good video 3CXfoxhallsolutions, thank you.
So the short explanation is that some routers have some bad NAT issues?
My logic is that if with certain router models everything is working "plug&play" while with others you have to make port forwards and scratch your head, the culprit is the router's software.
From a smart business point of view and mine, it is not worth it to just tweak and change various settings for each remote site.
Just change the router with a model that you know it is working.
Ease of mind and less complications for the future.

 

[3CXfoxhallsolutions]

Something like that ... But I think that you can be a bit more specific ... I noticed things got a bit more difficult after Draytek routers started to implement SPI firewalls ... However, they are not the only ones who have gone, or are moving that way ... So I think you'll see these issues more often than not!

best regards ...

 

[jpillow]

Inteq: Thats exactly what we do as you stated its not worth taking extra time tweaking each router for each location. After my first few customers with remote locations we simply use our routers at all ocations. I for the most part use Cisco RV series, and for clients that need a bit more protection, and dual band capabillityes the Cisco SA500 series works well. Its a lot easier to use what you know works everytime, same processes same tweaks if any needed.

 

[inteq]

From a TP LINK representative:

Thank you very much for your valuable feedback.
TL-ER5120 is a broadband router, and unable to work with IP phone.
Thank you in advance and look forward to your information.
If you need any further help please feel free to contact me.

Can I ask for more?

 

[lneblett]

I don't think that the terms Broadband and IP-Phone as used in the statement are mutually exclusive nor wholly descriptive. From the datasheet of the make and model for which the inquiry was made:

NAT -
One-to-One NAT
Multi-nets NAT
Virtual Server, DMZ Host, Port Triggering, UPnP
FTP/H.323/SIP/IPsec/PPTP ALG