The Effnet ROHC product portfolio consists of software products based on RObust Header Compression (ROHC) RFCs. ROHC is a header compression algorithm and protocol standardized by IETF. The Effnet ROHC product portfolio provides significant improvements in link efficiency for TCP traffic e.g. web, file transfers etc., RTP and UDP traffic e.g. real time, interactive and streaming applications and ESP traffic e.g. secure traffic over high BER, long RTT links.
ROHC is recommended by 3GPP for efficient use of radio resources since Release 4 onwards and even by 3GPP2 and WiMAX for similar reasons. It is an important component of the IP Multimedia Subsystem (IMS). ROHC is also used to improve efficiency in many other data networks such as satellite, WAN and ad-hoc (military applications) etc.
3GPP’s Long Term Evolution (LTE) project focuses on enhancing the Universal Terrestrial Radio Access (UTRA) and optimizing radio access architecture. LTE has adopted packet-switch technology using end-to-end IP communication instead of traditional circuit-switching. One of the LTE specifications, Packet Data Convergence Protocol (TS 36.323) specifies use of ROHC. It supports the following ROHC framework and profiles implemented in the form of various Effnet products:
|Effnet ROHC™||Uncompressed, RTP/UDP/IP, UDP/IP, ESP/IP||RFC 3095, RFC 4815|
|Effnet ROHC-IP™||IP||RFC 3843, RFC 4815|
|Effnet ROHC-TCP™||TCP/IP||RFC 4996|
|Effnet ROHCv2™||Uncompressed, RTP/UDP/IP, UDP/IP, ESP/IP, IP||RFC 5225|
The Effnet ROHC product portfolio can be optionally complemented with a test environment, Effnet HC-Sim™, which can simulate IP traffic with configurable link conditions, e.g. bit errors, packet loss, reordering etc.
Packet classification and context management is essential to header compression. Effnet provides this additional module together with the Effnet ROHC product family.
The VoIP enabler on wireless networks! Effnet ROHC™ is an important component to efficiently run VoIP services over wireless networks. Most of the RTP applications use UDP for signaling purposes and there are also many stand-alone UDP applications, so the support for IP/UDP compression adds further to the efficiency. There is significant demand for secure exchange of information which leads to increased header overhead. The capability to compress IP/ESP, the header overhead in secure connections, makes it possible to run secure networks without additional bandwidth.
As more and more networks are moving to support IP based communications, the number of nodes that require an IP address are increasing rapidly. The introduction of IPv6 should address this concern but at least during transition time, a lot of traffic will be sent via tunnels across networks. Effnet ROHC-IP™ is capable of compressing layers of IP headers thus making it possible to run tunneled traffic without need for additional bandwidth.
Multiple Internet packet size studies* are in agreement that at least 40% of all IPv4 packets carry no or only a few bytes of payload i.e. packet sizes are at or very near to header size (IPv4+TCP). One study of IPv6 packets shows the same trend. Even more remarkable in that study is that for IPv6, 60-80% of the packets carry more header data than packet data. Effnet ROHC-TCP™ would be very beneficial in these cases.
Mobility is the cornerstone of the cellular networks but supporting it efficiently is a tricky business. As the cellular network architectures have evolved, the integration point of ROHC in system nodes has moved closer towards mobile terminals for various reasons but has lead to a problem of handling reordering of packets during mobility. Effnet ROHCv2™ addresses this concern very efficiently while providing high compression efficiency and robustness.
*Packet size studies at www.caida.org