Applies To Customers



This article discusses the various registration states that a PBX user or Trunk can be in. It also discusses recommended expiry times and how this interacts with SIP REGISTER packets sent out.

Registration States Explained

GREEN DOT - Success, a register packet was sent and a a 2xx response was received. User should be ready for calling.

RED DOT - Failed, a register packet was sent, but no 2xx response was received

GREY/BLUE DOT - Registration is not enabled for this user. Typically this is intentional (e.g. PBX set to non-registration), but can also be if the user does not have a license associated.

ORANGE DOT - Pending, the very first registration is queued. This is not expected to be in this state for more than a few minutes.

ORANGE CIRCLE - Expired, registrations are working, but are not keeping up with the Expiry. Consider setting a longer Expiry on your PBX. An expired registration is still honoured by the platform, as long as the upstream PBX/Trunk is still able to process calls.

Registration Expiry

Registration expiry is the frequency with which the platform sends out REGISTER SIP packets to let the upstream PBX/Trunk service know that the platform is available to process phone calls for a given user(s). For a PBX a registration takes place per user. For a Trunk the registration takes place per trunk service.

An expiry time of 3600 seconds (1 hour) is recommended. A shorter expiry increases SIP load on both platform and the upstream PBX/Trunk. Other systems that run behind a NAT gateway might require a shorter expiry to keep the connection alive (TCP/TLS) or to keep the firewall hole open (NAT UPD), however the platform does not have either constraint and as such there is no need for a short expiry.

As the expiry timer counts towards zero the platform will send out a new registration. This typically happens within 10% of the expiry time. For example, a registration with a 1 hour expiry will typically renew between 0 and 6 minutes ahead of the hour. This is especially useful for large user accounts to spread out the load on the upstream PBX/Trunk. 

If a registration fails the platform will auto retry 5 minutes later, regardless of any expiry configured.