Datagram Congestion Control Protocol (DCCP) Parameters
- Created
- 2005-08-25
- Last Updated
- 2025-04-29
- Available Formats
-

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Registries Included Below
- Packet Types
- Reset Codes
- Option Types
- Feature Numbers
- Congestion Control Identifiers
- Ack Vector States
- Drop Codes
- Service Codes
- MP-DCCP Versions
- Multipath Options
- Multipath Key Type
Packet Types
- Registration Procedure(s)
-
Standards Action
- Reference
- [RFC4340]
- Available Formats
-

CSV
| 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 | DCCP-Listen | [RFC5596] |
| 11-13 | Unassigned | [RFC4340] |
| 14 | Reserved for experimental and testing use | [RFC4340] |
| 15 | Unassigned | [RFC4340] |
Reset Codes
- Reference
- [RFC4340]
- Available Formats
-

CSV
| Range | Registration Procedures | Note |
|---|---|---|
| 12-119 | IETF Review (IETF RFC publication) | |
| 120-126 | Reserved | For experimental and testing use |
| 127 | IETF Review (IETF RFC publication) | |
| 128-255 | CCID-specific codes | [1] |
| 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 | Encapsulated Port Reuse | [RFC6773] |
| 13 | Abrupt MP termination | [RFC-ietf-tsvwg-multipath-dccp-24] |
| 14-119 | Unassigned | [RFC4340] |
| 120-126 | Reserved | [RFC4340] |
| 127 | Unassigned | [RFC4340] |
| 128-255 | CCID-specific codes | [RFC4340] |
Option Types
- Reference
- [RFC4340]
- Available Formats
-

CSV
| Range | Registration Procedures | Note |
|---|---|---|
| 3-30 | IETF Review (IETF RFC publication) | |
| 45-119 | IETF Review (IETF RFC publication) | |
| 120-126 | Reserved | For experimental and testing use |
| 127 | IETF Review (IETF RFC publication) | |
| 128-255 | CCID-specific codes | [1] |
| 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 | Quick-Start Response | [RFC5634] |
| 46 | Multipath | [RFC-ietf-tsvwg-multipath-dccp-24] |
| 47-119 | Unassigned | [RFC4340] |
| 120-126 | Reserved | [RFC4340] |
| 127 | Unassigned | [RFC4340] |
| 128-255 | CCID-specific codes | [RFC4340] |
Feature Numbers
- Reference
- [RFC4340]
- Available Formats
-

CSV
| Range | Registration Procedures | Note |
|---|---|---|
| 10-119 | IETF Review (IETF RFC publication) | |
| 120-126 | Reserved | For experimental and testing use |
| 127 | IETF Review (IETF RFC publication) | |
| 128-255 | CCID-specific codes | [1] |
| 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 | Multipath Capable | [RFC-ietf-tsvwg-multipath-dccp-24] |
| 11-119 | Unassigned | [RFC4340] |
| 120-126 | Reserved | [RFC4340] |
| 127 | Unassigned | [RFC4340] |
| 128-255 | CCID-specific codes | [RFC4340] |
Congestion Control Identifiers
- Reference
- [RFC4340]
- Available Formats
-

CSV
| Range | Registration Procedures | Note |
|---|---|---|
| 0-1 | IETF Review (IETF RFC publication) | |
| 4-247 | IETF Review (IETF RFC publication) | |
| 248-254 | Reserved | For experimental and testing use |
| 255 | IETF Review (IETF RFC publication) |
| CCID | Description/Meaning | Reference |
|---|---|---|
| 0-1 | Unassigned | [RFC4340] |
| 2 | TCP-like Congestion Control | [RFC4341] |
| 3 | TFRC Congestion Control | [RFC4342] |
| 4 | TCP-Friendly Rate Control for Small Packets | [RFC5622] |
| 5-247 | Unassigned | [RFC4340] |
| 248-254 | Reserved | [RFC4340] |
| 255 | Unassigned | [RFC4340] |
Ack Vector States
- Registration Procedure(s)
-
Standards Action
- Reference
- [RFC4340]
- Available Formats
-

CSV
| State | Description/Meaning | Reference |
|---|---|---|
| 0 | Received | [RFC4340] |
| 1 | Received ECN Marked | [RFC4340] |
| 2 | Unassigned | [RFC4340] |
| 3 | Not Yet Received | [RFC4340] |
Drop Codes
- Registration Procedure(s)
-
Standards Action
- Reference
- [RFC4340]
- Available Formats
-

CSV
| 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] |
Service Codes
- Reference
- [RFC4340]
- Note
-
Service Codes can be found at the following: http://www.iana.org/assignments/service-codes
MP-DCCP Versions
- Registration Procedure(s)
-
RFC Required
- Reference
- [RFC-ietf-tsvwg-multipath-dccp-24]
- Available Formats
-

CSV
| Version | Value | Reference |
|---|---|---|
| 0 | 0000 | [RFC-ietf-tsvwg-multipath-dccp-24] |
| 1-15 | Unassigned |
Multipath Options
- Registration Procedure(s)
-
RFC Required
- Reference
- [RFC-ietf-tsvwg-multipath-dccp-24]
- Available Formats
-

CSV
| Multipath Option | Name | Description | Reference |
|---|---|---|---|
| MP_OPT=0 | MP_CONFIRM | Confirm reception/processing of an MP_OPT option | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.1] |
| MP_OPT=1 | MP_JOIN | Join subflow to an existing MP-DCCP connection | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.2] |
| MP_OPT=2 | MP_FAST_CLOSE | Close an MP-DCCP connection unconditionally | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.3] |
| MP_OPT=3 | MP_KEY | Exchange key material for MP_HMAC | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.4] |
| MP_OPT=4 | MP_SEQ | Multipath sequence number | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.5] |
| MP_OPT=5 | MP_HMAC | Hash-based message auth. code for MP-DCCP | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.6] |
| MP_OPT=6 | MP_RTT | Transmit RTT values and calculation parameters | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.7] |
| MP_OPT=7 | MP_ADDADDR | Advertise additional address(es)/port(s) | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.8] |
| MP_OPT=8 | MP_REMOVEADDR | Remove address(es)/ port(s) | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.9] |
| MP_OPT=9 | MP_PRIO | Change subflow priority | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.10] |
| MP_OPT=10 | MP_CLOSE | Close an MP-DCCP connection | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.11] |
| MP_OPT=11 | MP_EXP | Experimental option for private use | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.12] |
| MP_OPT>11 | Unassigned | Reserved for future Multipath options |
Multipath Key Type
- Registration Procedure(s)
-
RFC Required
- Reference
- [RFC-ietf-tsvwg-multipath-dccp-24]
- Available Formats
-

CSV
| Type | Name | Meaning | Reference |
|---|---|---|---|
| 0 | Plain Text | Plain text key | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.4] |
| 1-254 | Unassigned | Reserved for future use | |
| 255 | Experimental | For private use only | [RFC-ietf-tsvwg-multipath-dccp-24, Section 3.2.4] |
Footnote
| [1] |
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/dccp-ccid2-parameters.xhtml http://www.iana.org/assignments/dccp-ccid3-parameters/dccp-ccid3-parameters.xhtml http://www.iana.org/assignments/dccp-ccid4-parameters/dccp-ccid4-parameters.xhtml |