[rohc] CRC correction algorithms in ROHCv2
Anil Maguluri <Anil.Maguluri@lntinfotech.com> Mon, 21 December 2009 09:24 UTC
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From: Anil Maguluri <Anil.Maguluri@lntinfotech.com>
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Date: Mon, 21 Dec 2009 14:54:15 +0530
Thread-Topic: CRC correction algorithms in ROHCv2
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Subject: [rohc] CRC correction algorithms in ROHCv2
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Hi All, Please clarify whether my understanding is right or not. As per my understanding, there is no need of CRC Correction algorithms in ROHCv2 because every packet has CRC in ROHCv2. As you know the CRC Correction algorithms are clearly mentioned in ROHCv1 (RFC 3095). But, the RFC 5225 has the below information: "6.4. Reconstruction and Verification Validation of the IR header (8-bit CRC) The decompressor MUST always validate the integrity of the IR header using the 8-bit CRC carried within the IR header. When the header is validated, the decompressor updates the context with the information in the IR header. Otherwise, if the IR cannot be validated, the context MUST NOT be updated and the IR header MUST NOT be delivered to upper layers. Verification of CO headers (3-bit CRC or 7-bit CRC) The decompressor MUST always verify the decompression of a CO header using the CRC carried within the compressed header. When the decompression is verified and successful, the decompressor updates the context with the information received in the CO header; otherwise, if the reconstructed header fails the CRC verification, these updates MUST NOT be performed. A packet for which the decompression attempt cannot be verified using the CRC MUST NOT be delivered to upper layers. Decompressor implementations may attempt corrective or repair measures on CO headers prior to performing the above actions, and the result of any decompression attempt MUST be verified using the CRC." Please clarify the below queries. Is CRC Correction algorithms are used in ROHCv2? If yes, where did they mentioned the procedures? Thanks for your support. Regards, Anil Kumar Maguluri ________________________________ This Email may contain confidential or privileged information for the intended recipient (s) If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system. ______________________________________________________________________
- [rohc] CRC correction algorithms in ROHCv2 Anil Maguluri
- Re: [rohc] CRC correction algorithms in ROHCv2 Klaus Warnke