Jump to content

This is the support site for Andrews & Arnold Ltd, a UK Internet provider. Information on these pages is generally for our customers but may be useful to others, enjoy!

VoIP NAT: Difference between revisions

m
(Mention configuring the public address, or using a STUN server to obtain it)
 
(4 intermediate revisions by the same user not shown)
*SIP and NAT requires the call server, NAT device and phone to all play nicely and can still mean problems. There are a few specific cases we have tested and found reliable, but we cannot guarantee it will work in all cases or without some specific configuration settings
 
==Tips and recommendations for VoIP through NAT==
==NAT Tips==
If you do want to use NAT, then here are some tips if you are struggling to get calls working:
 
*'''Have your broadband with us.''' - we provide public IPs on all our connections.
*'''Disable UPnP''' on routers
*'''Disable SIP ALG''' on the router (or try enabling) See [[Disable SIP ALG]] - ALG can do funky things!
*Reduce the '''registration 'expiry'''' - try '''10 minutes''' (600 seconds) the default on devices us usually an hour. - helps keeps the registration active
*Set '''SIP Keepalive''' (if the phone has this option) to '''30 seconds''' - this helps keep the NAT session live on the router
*If the VoIP phone has a config setting to enter your external/public IP address, then enter the address of your router's WAN port
*Disable'''Enable Stun''' settings on the VoIP phone, or trydisable enablingstun it - stun.aa.net.uk can be used as the server name
*Enter firewall rules on the router to allow UDP traffic from our VoIP servers to your VoIP phone. See [[VoIP Firewall]] - usually not needed for NAT, but needed if you have public IPs
* '''Avoid ISPs that do CGNAT''' - that is NAT within their own network. - Having multiple levels of NAT between your handset and our service can cause problems in practice. Ask your ISP to provided you with a public IP address and no CGNAT.
 
If you have 2two similar VoIP phones behind a router using NAT, you willmay have to change the port settings on one phone.
The local SIP port (often 5060) and the local RTP port(s) can't be the same on the 2 phones - if they are the same, you'll
get weirdness on incoming calls.
autoreview, Bureaucrats, editor, Interface administrators, reviewer, Administrators
12,274

edits