telecom • networking • design

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ROHC – Robust Header Compression

ROHC improves the throughput on the link by compressing the TCP, UDP, IP and RTP headers to a a few bytes. This is particularly important for voice over IP as in absence of ROHC, the headers would have consumed more bandwidth than the voice channel being carried.

ROHC is envisioned as an extensible framework for robust and efficient header compression over highly error–prone links with long round–trip times. This design is motivated by the large bit error rates (typically on the order of 10−4 – 10−2) and long round trip times (typically 100–200 msec) of cellular networks. The design of ROHC is based on the experiences from the header compression schemes reviewed above. In particular, ROHC incorporates elements from ROCCO and Adaptive Header Compression (ACE) which may be viewed as a preliminary form of ROHC.