Network / Codec Changes

Further to our HD Voice announcement last week, please be advised of forthcoming changes to the Simwood Network.

SIP Termination

We have substantially extended our codec support to include a wide range of high quality wideband and ultra-wideband codecs as well as more performant narrowband codecs. Based on customer feedback we will now also accept HD codecs on all calls rather than only where the far end is HD capable. We will complete calls based on your highest preference codec wherever possible. All previously supported codecs remain supported and no action is required other than to take advantage of the new options.

We have also brought on-line a second global proxy in our second site. We will fail over to this in the event of an outage or maintenance affecting our primary site. Customers using IP addresses should take note but those using hostnames need take no action.

Full and current outbound interop information can be found in our knowledgebase.

SIP origination

Simwood numbering will be migrating to new equipment at approximately 7am GMT August 4th. At this time a few changes will take place which may require advance action by some customers:

  • Calls will originate from a new IP address. Customers authenticating our traffic by IP address will need to add this in advance.
  • Substantially more codec options will be presented including HD codecs and further narrowband options.
  • Customers will be given their highest preference codec wherever possible. This is a change in behaviour and it is therefore important that customers check their codec preferences and ensure they know what they are asking for as they will now get it. This is particularly relevant to Asterisk users.
  • If necessary for interop reasons, the codec selection can now be hard-coded at a per number level such that we will only offer that or those specified in our INVITE.

Current inbound interop information can be found in our knowledgebase.

IAX2 Origination

Given limited usage and technical benefit, IAX2 is now depreciated as a transport. Existing numbers will continue to work but customers are requested to migrate them to SIP at the earliest convenience. IAX2 support will be withdrawn on September 30th 2010.

By widening our codec base we hope to offer customers greater flexibility and ultimately to maintain higher quality calls across the network. The architectural changes necessary for this however have been significant and offer us a platform on which we can base further development.

Thank you for your continued interest and please do not hesitate to contact us with any queries.