End-to-End VoIP over MPLS Header Compression
AT&T
AT&T
VoIP over MPLS typically uses the encapsulation voice/RTP/UDP/IP/MPLS. For an MPLS VPN, the packet header is at least 48 bytes, while the voice payload is typically no more than 30 bytes. VoIP over MPLS header compression can significantly reduce the VoIP overhead through various compression mechanisms. This is important on access links where bandwidth is scarce, and can be important on backbone facilities, especially where costs are high (e.g., some global cross-sections). In this draft we propose to use RSVP extensions to signal the header compression context and other control messages between the ingress and egress LSR. We provide two approaches to determining the header compression context: a) re-use the methods in cRTP to determine the context, and b) re-use the methods in Swallow's and Berger's 'simple' approach to determine the context.