14.2.1. SIP Endpoints 
For the list of supported certified SIP clients please check the Common Compatibility
Matrix,
the "Unify Ready" certifications and the following links:
3rd Party Native SIP Clients can generally be connected to the OpenScape 4000 Gateway
without
any Project Specific Release (PSR).
The list of RFCs supported by OpenScape 4000 can be found in the SIP Connectivity
chapter.
In case the OpenScape 4000 Gateway do not conform to any of the published RFCs, any
encountered issue can be addressed via a Service Ticket and will be further evaluated.