Hypertext caching protocol: Difference between revisions

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{{for|the TCP congestion control algorithm|H-TCP}}

{{Mergefrom|HTCP|date=August 2008}}

{{WikifyMore citations needed|date=NovemberJanuary 20072024}}

{{HTTP}}

'''Hypertext Caching Protocol''' (abbreviated to '''HTCP''') is used for discovering [[HTTP]] caches and cached data, managing sets of HTTP caches and monitoring cache activity. It permits full request and response headers to be used in cache management and expands the ___domain of cache management to include monitoring a remote cache's additions and deletions, requesting immediate deletions and sending hints about web objects such as the third party locations of cacheable objects or unavailability of web objects.<ref name="Gourley2002">{{cite book |last1=Gourley |first1=David |last2=Totty |first2=Brian |last3=Sayer |first3=Marjorie |last4=Reddy |first4=Sailu |last5=Aggarwal |first5=Anshu |title=HTTP: the definitive guide |date=2002 |publisher=O'Reilly |___location=United States of America |isbn=9781565925090 |edition=First |url=https://www.academia.edu/37865720/_WEB_HTTP_The_Definitive_Guide_ |access-date=30 December 2023}}</ref>

==Features==

More about HTCP:

1. All multi-[[octet (computing)|octet]] HTCP protocol elements are transmitted in [[network byte order]]. All RESERVEDreserved 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.

2. Any hostnames[[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 System|DNS]] names. Use of private names or addresses will require special operational care.

3.[[User Datagram Protocol|UDP]] must be supported. HTCP agents must not be isolated from NETWORKnetwork 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 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 Protocol|TCP]] and [[Domain Name System|UDP]] port number for HTCP.

An HTCP Message has the following general format:

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| AUTH | optional authentication for transaction

+---------------------+

==See also==

* [[Internet Cache Protocol]]

== References ==

{{reflist}}

==External links==

*{{Sum RFC|2756}}

*RFC 2756 - the [[request for comment]] on HTCP

[[Category:HTTPWeb caching protocol]]

[[Category:Internet protocols]]