
Datagram Congestion Control Protocol (DCCP) Parameters 

(last updated 2006-05-11)

Registries included below:
- Packet Types
- Reset Codes
- Option Types
- Feature Numbers
- Congestion Control Identifiers
- Ack Vector States
- Drop Codes
- Service Codes


Registry Name: Packet Types 
Reference: [RFC4340]
Registration Procedures: Standards Track RFC

Registry:
Type    Description/Meaning                          Reference
-----   -------------------------------------------  ---------
0       DCCP-Request                                 [RFC4340]
1       DCCP-Response                                [RFC4340]
2       DCCP-Data                                    [RFC4340]
3       DCCP-Ack                                     [RFC4340]
4       DCCP-DataAck                                 [RFC4340]
5       DCCP-CloseReq                                [RFC4340]
6       DCCP-Close                                   [RFC4340]
7       DCCP-Reset                                   [RFC4340]
8       DCCP-Sync                                    [RFC4340]
9       DCCP-SyncAck                                 [RFC4340]
10-13   Unassigned                                   [RFC4340]
14      Reserved for experimental and testing use    [RFC4340]
15      Unassigned                                   [RFC4340]


Registry Name: Reset Codes 
Reference: [RFC4340]
Range       Registration Procedures                  Notes
----------  ---------------------------------------  ----------------------------------------  
12-119      IETF Consensus (IETF RFC publication)
120-126     Reserved                                 For experimental and testing use   
127         IETF Consensus (IETF RFC publication)
128-255     CCID-specific codes                      See 'Note for CCID-specific codes' below

Registry:
Reset Code  Name                                      Reference
----------  ----------------------------------------  ---------
0           Unspecified                               [RFC4340]
1           Closed                                    [RFC4340]                  
2           Aborted                                   [RFC4340]
3           No Connection                             [RFC4340] 
4           Packet Error                              [RFC4340]      
5           Option Error                              [RFC4340]     
6           Mandatory Error                           [RFC4340] 
7           Connection Refused                        [RFC4340]    
8           Bad Service Code                          [RFC4340]    
9           Too Busy                                  [RFC4340]       
10          Bad Init Cookie                           [RFC4340]      
11          Aggression Penalty                        [RFC4340]  
12-119      Unassigned                                [RFC4340]                              
120-126     Reserved                                  [RFC4340]
127         Unassigned                                [RFC4340]
128-255     CCID-specific codes                       [RFC4340] 


Registry Name: Option Types 
Reference: [RFC4340]
Range       Registration Procedures                  Notes
----------  ---------------------------------------  ----------------------------------------   
3-30        IETF Consensus (IETF RFC publication)
45-119      IETF Consensus (IETF RFC publication)
120-126     Reserved                                 For experimental and testing use   
127         IETF Consensus (IETF RFC publication)
128-255     CCID-specific codes                      See 'Note for CCID-specific codes' below

Registry:
Type        Description/Meaning                          Reference
----------  -------------------------------------------  ---------
0           Padding                                      [RFC4340]          
1           Mandatory                                    [RFC4340]
2           Slow Receiver                                [RFC4340]
3-30        Unassigned                                   [RFC4340]
31          Reserved for experimental and testing use    [RFC4340]
32          Change L                                     [RFC4340]
33          Confirm L                                    [RFC4340]
34          Change R                                     [RFC4340]
35          Confirm R                                    [RFC4340]
36          Init Cookie                                  [RFC4340]
37          NDP Count                                    [RFC4340]
38          Ack Vector [Nonce 0]                         [RFC4340]
39          Ack Vector [Nonce 1]                         [RFC4340]
40          Data Dropped                                 [RFC4340]
41          Timestamp                                    [RFC4340]
42          Timestamp Echo                               [RFC4340]
43          Elapsed Time                                 [RFC4340]
44          Data Checksum                                [RFC4340]
45-119      Unassigned                                   [RFC4340]
120-126     Reserved                                     [RFC4340]
127         Unassigned                                   [RFC4340]
128-255     CCID-specific codes                          [RFC4340] 


Registry Name: Feature Numbers 
Reference: [RFC4340]
Range       Registration Procedures                  Notes
----------  ---------------------------------------  -----------------------------------------   
10-119      IETF Consensus (IETF RFC publication)
120-126     Reserved                                 For experimental and testing use   
127         IETF Consensus (IETF RFC publication)
128-255     CCID-specific codes                      See 'Note for CCID-specific codes' below

Registry:
Number      Description/Meaning                       Reference
----------  ----------------------------------------  ---------
0           Reserved                                  [RFC4340]
1           Congestion Control ID (CCID)              [RFC4340]
2           Allow Short Seqnos                        [RFC4340]
3           Sequence Window                           [RFC4340]
4           ECN Incapable                             [RFC4340]
5           Ack Ratio                                 [RFC4340]
6           Send Ack Vector                           [RFC4340]
7           Send NDP Count                            [RFC4340] 
8           Minimum Checksum Coverage                 [RFC4340]
9           Check Data Checksum                       [RFC4340]
10-119      Unassigned                                [RFC4340]
120-126     Reserved                                  [RFC4340]
127         Unassigned                                [RFC4340]
128-255     CCID-specific codes                       [RFC4340]  
 

Registry Name: Congestion Control Identifiers
Reference: [RFC4340]
Range       Registration Procedures                  Notes
----------  ---------------------------------------  ----------------------------------   
0-1         IETF Consensus (IETF RFC publication)
4-247       IETF Consensus (IETF RFC publication)
248-254     Reserved                                 For experimental and testing use   
255         IETF Consensus (IETF RFC publication)

Registry:
CCID        Description/Meaning                 Reference
----------  ----------------------------------  ---------
0-1         Unassigned                          [RFC4340]
2           TCP-like Congestion Control         [RFC4341]
3           TFRC Congestion Control             [RFC4342]
4-247       Unassigned                          [RFC4340]
248-254     Reserved                            [RFC4340]
255         Unassigned                          [RFC4340]


Registry Name: Ack Vector States
Reference: [RFC4340]
Registration Procedures: Standards Track RFC

Registry:
State     Description/Meaning            Reference
--------  -----------------------------  ---------
0         Received                       [RFC4340] 
1         Received ECN Marked            [RFC4340]
2         Unassigned                     [RFC4340]
3         Not Yet Received               [RFC4340] 


Registry Name: Drop Codes
Reference: [RFC4340]
Registration Procedures: Standards Track RFC

Registry:
Drop Code   Description/Meaning            Reference
----------  -----------------------------  ---------
0           Protocol Constraints           [RFC4340]
1           Application Not Listening      [RFC4340]
2           Receive Buffer                 [RFC4340]
3           Corrupt                        [RFC4340]
4-6         Unassigned                     [RFC4340]
7           Delivered Corrupt              [RFC4340] 


Registry Name: Service Codes 
Reference: [RFC4340]
Registration Procedures: Specification Required or First Come First Serve (FCFS)
Service Codes can be found at the following:
http://www.iana.org/assignments/service-codes


Note for CCID-specific codes:
DCCP Reset Codes 128-255, Option Types 128-255, and Feature Numbers 
128-255 are reserved for CCID-specific use.  Each DCCP CCID (that is, 
each entry in the DCCP Congestion Control Identifiers registry) may 
create registries for its CCID-specific Reset Code, Option Type, and 
Feature Number ranges.  These CCID-specific registries are independent: 
different CCIDs can allocate the same value (such as Feature Number 128) 
for different purposes.  [RFC4340], Section 10.3, 
describes how DCCP decides which registry applies for a given 
CCID-specific Reset Code, Option Type, or Feature Number.  In each case, 
CCID-specific registries may only register values 128-255; values 0-127 
are registered here.  For examples, see the following:

http://www.iana.org/assignments/dccp-ccid2-parameters
http://www.iana.org/assignments/dccp-ccid3-parameters


References
----------
[RFC4340]  E. Kohler, M. Handley and S. Floyd, "Datagram Congestion 
           Control Protocol (DCCP)", RFC 4340, March 2006.

[RFC4341]  S. Floyd and E. Kohler, "Profile for DCCP Congestion Control 
           ID 2: TCP-like Congestion Control", RFC 4341, March 2006.

[RFC4342]  S. Floyd, E. Kohler and J. Padhye, "Profile for DCCP Congestion 
           Control ID 3: TFRC Congestion Control", RFC 4342, March 2006.
   
(created 2005-08-25)

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