Because of ongoing improvements to improve security and performance we have planned to following maintenance.
Phase 1, 2nd of April, 2020
On the 2nd of April, 2020 we are going to update our certificates for sgw01.cm.nl and sgw02.cm.nl and we will move sgw01.cm.nl to a new IP address: 188.8.131.52. You can already find our new certificates on https://gw.cmtelecom.com/certs/sgw01.pem.txt
Phase 2, 20th until 24th of April, 2020
Between the 20th and 24th of April, 2020 the IP addresses of the services that send status reports (SR) and incoming messages (MO) will be changed. The IP ranges that could be used for our outbound traffic are:
Note: You should whitelist the IP range. We cannot guarantee an exact IP addresses of specific services within these ranges as the servers can change IP within this range at any time.
Phase 3, 16th of June, 2020
On the 16th of June, 2020 we will stop support for TLS1.1 on our gateways. Since TLS 1.1 can be a potential security risk (as confirmed by many security organizations) we advise to start using at least version TLS 1.2 for communication towards our gateways.