SIP Provider British Telecom One Voice SIP Trunk (UK)

General

The One Voice SIP Trunk from British Telecom (BT) was first tested and released with a SwyxWare 2015 R3. 

The One Voice SIP Trunk from BT is a registerless SIP trunk. This means that the authentication is based on the public IP address of the SwyxWare server. Therefore, you need a static, public IP address from your ISP assigned to the SwyxWare server.

Platforms

SwyxWare

The One Voice SIP Trunk from BT can be used according to the settings listed below from SwyxWare 2015  R3.

SwyxON

The One Voice SIP Trunk from BT is not released for central connection in the data center.

Configuration

During creation of the SIP Trunkgroup, the profile 'British Telecom (UK)' must be selected.

BT is operating with a number of different servers. Therefore it is not possible to preconfigure the Proxy Server in the "SIP" tab of the Trunkgroup Properties dialog. In this field, please enter the IP address that BT has named you.

In case that the SwyxWare server is running with a private IP address and the static, public IP address is provided by NAT gateway, it is necessary to configure a STUN server in the properties of the SIP trunk group, under the tab 'SIP'. A list of public STUN servers can e.g. be found at  http://www.voip-info.org/wiki/view/STUN. In this case, it is necessary to configure the correct portwarding in the NAT gateway, such that inbound SIP requests are being forwarded to port 65002 of the SwyxWare server.

If no NAT gateway is necessary, the BT SIP trunk has to be configured such that inbound SIP requests are being directly sent to port 65002 of the SwyxWare server.

For additional information, it is possible to download a configuration guide at the end of this article.

Session-Interval
BT expects a Session interval of 600 (seconds) on outbound calls. The prevent reINVITES which would slow down the call establishment, underneath the registry key  HKLM\Software\Wow6432Node\Swyx\LinkMgr\CurrentVersion\Options two new DWORD values SipMinSessionTimerIntervalSeconds and SipSessionTimerIntervalSeconds  can be created with an assigned value of 600 (decimal). After creating this value, the LinkMgr service must be restarted.
Important: This setting will affect all SIP Trunks.

Tested Features

• Incoming/outgoing national calls
• Correct Calling Line Identification (CLI) on national
• CLIP No Screening
• Holding and retrieving calls
• Toggeling between two calls
• Call transfer
• Conferencing
• Mutually supported codecs: G.711a/ G.711µ/ G.729/ T.38 for FAX negotiation
• Incoming/outgoing DTMF signaling in accordance with via RFC2833
• T.38 Negotiation and FAX transmission

Restrictions

None

Tests

21/01/2016 with SwyxWareV2015R3

Disclaimer

Verifying interoperability between different SIP providers and the Swyx solution is part of the Enreach Technology Alliance Programme (TAP) tasks. Due to different implementations of the SIP RFCs, it is necessary to determine and provide an individual configuration for each SIP provider.

Within the TAP, Enreach tests a large number of national and international SIP providers in order to make statements about the interoperability with the Swyx solution and the functional scope of the respective SIP trunk. These results and, if needed, configuration advice are published in Help Center articles.

Enreach is in close contact with selected SIP providers to ensure a quick troubleshooting in case of incompatibilities. In addition, tests are repeated at regular intervals to ensure consistent quality.

Despite regular retests it cannot be excluded that incompatibilities with the Swyx solution may occur due to changes in the SIP connection on the provider side or that the provided profile is no longer valid. After creating the trunk group or SIP trunk, the profile settings should be compared with the provider's information and adjusted accordingly in case of deviations.

However, should incompatibilities or problems occur with a tested SIP trunk, no claims for recourse against Enreach GmbH can be derived from this. In such cases, you can contact Enreach Support via your specialist dealer.

The third-party contact information included in this article is provided to help you find the technical support you need. This contact information is subject to change without notice. Swyx in no way guarantees the accuracy of this third-party contact information nor is responsible for it's content.