Hypertext caching protocol: Difference between revisions

Revision as of 09:01, 30 March 2011

Revision as of 00:48, 6 September 2011

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==Features==

All multi-[[octet (computing)|octet]] HTCP protocol elements are transmitted in [[network byte order]]. All reserved fields should be set to binary zero by senders and left unexamined by receivers. Headers must be presented with the [[CRLF]] line termination, as in HTTP.

Any [[hostname]]s specified should be compatible between sender and receiver, such that if a private naming scheme (such as HOSTS.TXT or NIS) is in use, names depending on such schemes will only be sent to HTCP neighbors who are known to participate in said schemes. Raw addresses (dotted quad [[IPv4]], or colon-format [[IPv6]]) are universal, as are public [[Domain_Name_SystemDomain Name System|DNS]] names. Use of private names or addresses will require special operational care.

[[User Datagram Protocol|UDP]] must be supported. HTCP agents must not be isolated from network failures and delays. An HTCP agent should be prepared to act in useful ways when no response is forthcoming, or when responses are delayed or reordered or damaged. [[Transmission_Control_ProtocolTransmission Control Protocol|TCP]] is optional and is expected to be used only for protocol debugging. The [[Internet Assigned Numbers Authority|IANA]] has assigned port 4827 as the standard [[Transmission_Control_ProtocolTransmission Control Protocol|TCP]] and [[Domain_Name_SystemDomain Name System|UDP]] port number for HTCP.

An HTCP Message has the following general format: