|CRANE, Common Reliable Accounting for Network Element|
|Protocol type:||Application layer protocol.|
|Port:||TBD (SCTP, TCP).|
TCP and SCTP are two transport layer protocols that fulfill the reliability requirement of CRANE. Either one of them MAY be used to transport CRANE messages. TCP meets some of the requirements, but not all (e.g., quick detection of server failure, the fact that TCP is stream oriented and not record oriented). Therefore, SCTP is the preferred way to transmit CRANE messages.
|MAC header||IP header||TCP | SCTP header||CRANE header||Data :::|
Indicates the supported CRANE protocol implementation. This field MUST be set to 1 to indicate the CRANE protocol Version 1.0. CRANE protocol Version 1.0 only supports IPv4 addressing; however, it can be used to transfer information related to IPv6 flows.
Identifies the type of the message.
|0x01||START, Flow Start.|
|0x02||START ACK, Flow Start Acknowledge.|
|0x03||STOP, Flow Stop.|
|0x04||STOP ACK, Flow Stop Acknowledge.|
|0x10||TMPL DATA, Template Data.|
|0x11||TMPL DATA ACK, Template Data Acknowledge.|
|0x12||FINAL TMPL DATA, Final Template Data.|
|0x13||FINAL TMPL DATA ACK, Final Template Data Ack.|
|0x14||GET SESS, Get Sessions.|
|0x15||GET SESS RSP, Get Sessions Response.|
|0x16||GET TMPL, Get Template.|
|0x17||GET TMPL RSP, Get Template Response.|
|0x18||START NEGOTIATE, Start Negotiation.|
|0x19||START NEGOTIATE ACK, Start Negotiation Ack.|
|0x21||DATA ACK, Data Acknowledge.|
|0x30||STATUS REQ, Status Request.|
|0x31||STATUS RSP, Status Response.|
Identifies the session with which the message is associated. This field is ignored in the case of GET SESS and GET SESS RSP messages.
Used to identify options associated with the message. For CRANE Version 1.0, all the flags are reserved. The flags are set to zero on transmit and are ignored on receipt.
Total length of the CRANE message in bytes including the header.
Data. Variable length.
(RFC 3423) A CRANE Session is a logical connection between a CRANE client and one or multiple CRANE servers for the purpose of delivering accounting data. Multiple sessions MAY be maintained concurrently in a CRANE client or a CRANE server; they are distinguished by Session IDs.
(RFC 3423) A collection of information gathered by the Network Element for various purposes, e.g., accounting. The structure of a Data Record is defined by a Template.
DSN, Data Sequence Number.
(RFC 3423) An accounting Data Record level sequence number, which is attached to all data messages to facilitate reliable and in-sequence delivery.
(RFC 3423) A CRANE server is assigned with a Priority value. Accounting data is always delivered to the perceived operating CRANE server (from the CRANE client point of view) with the highest Priority value (the primary server) within a CRANE Session.
(RFC 3423) Defines the structure of any types of Data Record, and specifies the data type, meaning, and location of the fields in the record.
[RFC 3423] XACCT's Common Reliable Accounting for Network Element (CRANE) Protocol Specification Version 1.0.
[RFC 3955] Evaluation of Candidate Protocols for IP Flow Information Export (IPFIX).