Update - Just to further advise customers, during this maintenance window (3-5am on a Sunday) we will be re-pointing various DNS entries for our Gradwell VoIP services so that traffic routes to our new platform located in Amazon Web Services. As a result, customers will see phone calls going to and from AWS, rather than our Telehouse datacentre.

This work will only impact Hosted PBX and SIP Trunking calls, and not IAX trunk calls.

In preparation for this testing, we would like to recommend customers using IP firewalling ensure that their firewall rules are up to date and include all of our IP addresses.

Particularly, you should expect to send and receive VoIP traffic from the following additional IP addresses:
3.9.45.177, 35.176.199.55, 35.177.2.133, 35.177.5.6, 35.177.89.52, 35.178.61.16

Information on the IP addresses Gradwell may send traffic from can be found here:
https://support.gradwell.com/hc/en-gb/articles/215553563

Customers who do not perform IP filtering in their network will not need to make any changes ahead of this recovery testing.

Thank you for your understanding of the necessity of this maintenance as we work to bring increased reslilience to our telecoms services.
May 16, 15:08 BST