SIP Trunking - Peering Method

A Peering Trunk enables a trusted network-to-network connection between your SIP PBX and the 2talk Voice Platform. The main advantage of Peering is greater flexibility of number routing within your onsite-PBX.

To use the Peering Method you need a static IP address that is publicly routable.

Option 1: Configure an entire account as a Peering Account

Please note: You cannot have SIP Peering enabled on an account at the same time as logging in/registering from another phone/device.  When you enable SIP trunking on your account you instruct the 2talk Platform to always send calls to your IP-PBX system and nowhere else.  If you try to login/register to 2talk on one of your numbers while SIP trunking is enabled then your login/registration will fail.

To turn on account level peering first ensure that your IP-PBX is configured correctly and ready to receive calls from 2talk. Then follow these steps:

  • Decide which number you wish to act as you 'pilot' number (primary number) on your trunk and select this number in the Cloud PBX page
  • Expand the Preferences features settings option and select SIP Peering
  • Tick the 'Enable SIP Peering' checkbox
  • Enter the static IP address of your IP-PBX in the 'Primary Host IP Address' text box
  • If you have a second IP-PBX to act as a 'failover' host then enter this in the next text box (This is an optional field)
  • If you do not wish to lose any existing settings on your 2talk lines then tick the 'Do not reset my line settings' box. Usually, a number of features are automatically disabled when you enable SIP trunking on your account such as Voicemail, call transfer features etc. since these features are usually handled by your IP-PBX platform.
  • Click Save when Done

SIP OPTIONS polling enabled

2talk poll the primary trunk IP every minute.

If no response to the SIP OPTIONS  is detected 3 additional OPTIONS checks are made within the next minute to rule out a dropped packet. 

If there are no further responses the trunk fails over to the secondary IP (if configured) if not then it  call forward unreachable logic is followed.

When failed over all calls on the trunk are routed to the failover IP.

In the background 2talk continue to poll the primary IP and once it has responded again/recovered will start routing calls to the primary IP again.


SIP OPTIONS polling disabled

If SIP OPTIONS polling is not enabled calls are only failed over on SIP timeout, which is 30 seconds.

This timeout applies for every call which can result in a negative experience for the inbound caller, waiting up to 30 seconds before the call starts to connect.

As a result 2talk recommend adding SIP OPTIONS but only if the customer PBX correctly supports responding to OPTIONs otherwise 2talk will failover the trunk immediately as soon as the feature is enabled which can cause issues.

The response to OPTIONS can be any response, all that is needed is some sort of response.  For example the response can be an 200 OK or a 404 Not Found.

Outbound calls routing is determined by the end device.  If an exception route has been configured 2talk will trust outbound calls from either of the IP's configured.

Option 2: Configure individual lines on an account as Peers
If you wish to be able to register and peer lines on the same account then you will need to set up an individual trunk for each line you wish to peer to your PBX in the Cloud PBX Number Manager page.

Two fields to configure the peering IP will be available for each line - Primary IP and Failover IP. Enter your primary host IP and your failover host IP (optional) in the labelled fields and click 'Save' at the bottom of the page.

Click Save to confirm the settings

Lines that are not set up as Peering Lines can be registered to devices