INTERNET - DRAFT Expires : 28

The Datagram Congestion Control Protocol (DCCP) is a transport protocol that provides bidirectional unicast connections of congestion-controlled unreliable datagrams. DCCP is suitable for applications that transfer fairly large amounts of data, but can benefit from control over the tradeoff between timeliness and reliability. Kohler/Handley/Floyd [Page 1] INTERNET-DRAFT Expires: 28 May 2006 November 2005 TO BE DELETED BY THE RFC EDITOR UPON PUBLICATION: Changes since draft-ietf-dccp-spec-08.txt: * Added minimum Sequence Window. * Init Cookie implementation sketch. * Include reasoning for ignoring options on DCCP-Data. * More Aggression Penalty explanation. * More explanation on Ack Vectors that report information on packets that haven’t been sent. Changes since draft-ietf-dccp-spec-07.txt: * Many changes, not listed here, for WGLC. * The more stringent Sequence Number checks on DCCP-Sync and DCCPSyncAck packets become SHOULD, not MAY. Changes since draft-ietf-dccp-spec-06.txt: * Change extended sequence numbers. Now 48-bit sequence numbers are MANDATORY, and all packet types except Data, Ack, and DataAck always use 48-bit sequence numbers. This change improves DCCP’s robustness against blind attacks. * Removed empty Change options. * Allow preference list changes during feature negotiations (this seems easier to implement than the alternative). This required a new feature negotiation state, UNSTABLE. * Add Minimum Checksum Coverage feature. * Add Reset Congestion State option. * Simplify the implementation of CCID-specific option processing: no need to check whether the CCID feature is being negotiated. * Many more minor changes. Changes since draft-ietf-dccp-spec-05.txt: * Organization overhaul. Kohler/Handley/Floyd [Page 2] INTERNET-DRAFT Expires: 28 May 2006 November 2005 * Add pseudocode for event processing. * Remove # NDP; replace with Ack Count. * Remove Identification, Challenge, ID Regime, and Connection Nonce. * Data Checksum (formerly Payload Checksum) uses a 32-bit CRC. * Switch location of non-negotiable features to clarify presentation; now the feature location controls its value. * Rename "value type" to "reconciliation rule". * Rename "Reset Reason" to "Reset Code". * Mobility ID becomes 128 bits long. * Add probabilities to Mobility ID discussion.