Patent ID: 7468983

Claim:
A method comprising: transferring from the first communication device to the second communication device, via the at least one network element that is neither the first communication device nor the second communication device, a message indicating at least one codec that the first communication device supports for a session between the first communication device and the second communication device, the message further indicating, from a plurality of operational modes of said at least one codec, first supported operational modes that the first communication device supports for the session; and removing unsupported operational modes of said at least one codec by the at least one network element to obtain second supported operational modes of said at least one codec, and indicating said second supported operational modes of said at least one codec in an attribute line of a session description protocol message body in the message, wherein the supported and unsupported operational modes are indicated with the aid of a mask having a plurality of mask elements each mask element being representative of one operational mode, wherein each of the plurality of the mask elements indicates whether the corresponding operational mode is supported wherein: the mask element taking a first value indicates that the operational mode is supported and the mask element taking a second value indicates that the operational mode is unsupported, wherein the mask comprises a binary mask and the mask elements comprise binary digits.