Negotiation of message chunk size for message session relay protocol session

Embodiments of the invention relates to methods, and apparatuses for exchanging the preferred MSRP chunk sizes between an end-point and a remote end-point, directly or via a server using SDP offer/answer mechanism. The preferred MSRP chunk size may be the maximum allowed MSRP chunk size for the end-point and may be determined in accordance with network/link conditions and/or internal configuration. The end-point uses its preferred MSRP chunk size and the received preferred MSRP chunk size of the remote end-point to determine the MSRP chunk size that will be used to segment the messages from the end-point to the remote-end-point over the MSRP session. The preferred MSRP chunk size can be renegotiated during an ongoing MSRP session.