| Description | This article explains why RCS (Rich Communication Services) text messaging between Apple and Android phones could be blocked by the FortiGate firewall. |
| Scope | FortiGate. |
| Solution |
RCS (Rich Communication Services) messaging is a mobile carrier messaging system that was introduced as a replacement for SMS/MMS. It is intended to provide an upgraded experience to texting and allow features such as read receipts or 'typing' indicators.
It is implemented on each mobile operating system based on the same Industry standards which require that RCS-capable devices connect to exchange servers on ports 443 and 5223. This traffic falls under the 'Instant Messaging' category of the web-filtering profile and is set to 'Allow' by default on the FortiGate firewall.
If a non-default profile is in use and 'Instant messaging' is blocked, RCS messages will be blocked between these iOS (Apple) and Android devices. This is due to certain differences in how each operating system retrieves RCS server IP addresses. As expected, this can be resolved by setting this category back to 'Allow'.
Note: Blocking 'Instant Messaging' only blocks RCS between IOS and Android or vice versa. It does not affect RCS messaging between devices on the same operating system. |
