5. Attributes
RADIUS Attributes carry the specific authentication, authorization and accounting details for the request and response.
Some attributes MAY be included more than once. The effect of this is attribute specific, and is specified in each attribute description.
The end of the list of attributes is indicated by the Length of the RADIUS packet.
A summary of the attribute format is shown below. The fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
The Type field is one octet. Up-to-date values of the RADIUS Type field are specified in the most recent "Assigned Numbers" RFC [6]. Values 192-223 are reserved for experimental use, values 224-240 are reserved for implementation-specific use, and values 241-255 are reserved and should not be used. This specification concerns the following values:
| Value | Attribute |
|---|---|
| 1-39 | (refer to RADIUS document [2]) |
| 40 | Acct-Status-Type |
| 41 | Acct-Delay-Time |
| 42 | Acct-Input-Octets |
| 43 | Acct-Output-Octets |
| 44 | Acct-Session-Id |
| 45 | Acct-Authentic |
| 46 | Acct-Session-Time |
| 47 | Acct-Input-Packets |
| 48 | Acct-Output-Packets |
| 49 | Acct-Terminate-Cause |
| 50 | Acct-Multi-Session-Id |
| 51 | Acct-Link-Count |
| 60+ | (refer to RADIUS document [2]) |
Length
The Length field is one octet, and indicates the length of this attribute including the Type, Length and Value fields. If an attribute is received in an Accounting-Request with an invalid Length, the entire request MUST be silently discarded.
Value
The Value field is zero or more octets and contains information specific to the attribute. The format and length of the Value field is determined by the Type and Length fields.
Note that none of the types in RADIUS terminate with a NUL (hex 00). In particular, types "text" and "string" in RADIUS do not terminate with a NUL (hex 00). The Attribute has a length field and does not use a terminator. Text contains UTF-8 encoded 10646 [7] characters and String contains 8-bit binary data. Servers and servers and clients MUST be able to deal with embedded nulls. RADIUS implementers using C are cautioned not to use strcpy() when handling strings.
The format of the value field is one of five data types. Note that type "text" is a subset of type "string."
-
text — 1-253 octets containing UTF-8 encoded 10646 [7] characters. Text of length zero (0) MUST NOT be sent; omit the entire attribute instead.
-
string — 1-253 octets containing binary data (values 0 through 255 decimal, inclusive). Strings of length zero (0) MUST NOT be sent; omit the entire attribute instead.
-
address — 32 bit value, most significant octet first.
-
integer — 32 bit unsigned value, most significant octet first.
-
time — 32 bit unsigned value, most significant octet first — seconds since 00:00:00 UTC, January 1, 1970. The standard Attributes do not use this data type but it is presented here for possible use in future attributes.
5.1. Acct-Status-Type
Description
This attribute indicates whether this Accounting-Request marks the beginning of the user service (Start) or the end (Stop).
It MAY be used by the client to mark the start of accounting (for example, upon booting) by specifying Accounting-On and to mark the end of accounting (for example, just before a scheduled reboot) by specifying Accounting-Off.
A summary of the Acct-Status-Type attribute format is shown below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
40 for Acct-Status-Type.
Length
6
Value
The Value field is four octets.
| Value | Meaning |
|---|---|
| 1 | Start |
| 2 | Stop |
| 3 | Interim-Update |
| 7 | Accounting-On |
| 8 | Accounting-Off |
| 9-14 | Reserved for Tunnel Accounting |
| 15 | Reserved for Failed |
5.2. Acct-Delay-Time
Description
This attribute indicates how many seconds the client has been trying to send this record for, and can be subtracted from the time of arrival on the server to find the approximate time of the event generating this Accounting-Request. (Network transit time is ignored.)
Note that changing the Acct-Delay-Time causes the Identifier to change; see the discussion under Identifier above.
A summary of the Acct-Delay-Time attribute format is shown below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
41 for Acct-Delay-Time.
Length
6
Value
The Value field is four octets.
5.3. Acct-Input-Octets
Description
This attribute indicates how many octets have been received from the port over the course of this service being provided, and can only be present in Accounting-Request records where the Acct-Status-Type is set to Stop.
A summary of the Acct-Input-Octets attribute format is shown below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
42 for Acct-Input-Octets.
Length
6
Value
The Value field is four octets.
5.4. Acct-Output-Octets
Description
This attribute indicates how many octets have been sent to the port in the course of delivering this service, and can only be present in Accounting-Request records where the Acct-Status-Type is set to Stop.
A summary of the Acct-Output-Octets attribute format is shown below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
43 for Acct-Output-Octets.
Length
6
Value
The Value field is four octets.
5.5. Acct-Session-Id
Description
This attribute is a unique Accounting ID to make it easy to match start and stop records in a log file. The start and stop records for a given session MUST have the same Acct-Session-Id. An Accounting-Request packet MUST have an Acct-Session-Id. An Access-Request packet MAY have an Acct-Session-Id; if it does, then the NAS MUST use the same Acct-Session-Id in the Accounting-Request packets for that session.
The Acct-Session-Id SHOULD contain UTF-8 encoded 10646 [7] characters.
For example, one implementation uses a string with an 8-digit upper case hexadecimal number, the first two digits increment on each reboot (wrapping every 256 reboots) and the next 6 digits counting from 0 for the first person logging in after a reboot up to 2^24-1, about 16 million. Other encodings are possible.
A summary of the Acct-Session-Id attribute format is shown below. The fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Text ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
44 for Acct-Session-Id.
Length
= 3
String
The String field SHOULD be a string of UTF-8 encoded 10646 [7] characters.
5.6. Acct-Authentic
Description
This attribute MAY be included in an Accounting-Request to indicate how the user was authenticated, whether by RADIUS, the NAS itself, or another remote authentication protocol. Users who are delivered service without being authenticated SHOULD NOT generate Accounting records.
A summary of the Acct-Authentic attribute format is shown below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
45 for Acct-Authentic.
Length
6
Value
The Value field is four octets.
| Value | Meaning |
|---|---|
| 1 | RADIUS |
| 2 | Local |
| 3 | Remote |
5.7. Acct-Session-Time
Description
This attribute indicates how many seconds the user has received service for, and can only be present in Accounting-Request records where the Acct-Status-Type is set to Stop.
A summary of the Acct-Session-Time attribute format is shown below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
46 for Acct-Session-Time.
Length
6
Value
The Value field is four octets.
5.8. Acct-Input-Packets
Description
This attribute indicates how many packets have been received from the port over the course of this service being provided to a Framed User, and can only be present in Accounting-Request records where the Acct-Status-Type is set to Stop.
A summary of the Acct-Input-packets attribute format is shown below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
47 for Acct-Input-Packets.
Length
6
Value
The Value field is four octets.
5.9. Acct-Output-Packets
Description
This attribute indicates how many packets have been sent to the port in the course of delivering this service to a Framed User, and can only be present in Accounting-Request records where the Acct-Status-Type is set to Stop.
A summary of the Acct-Output-Packets attribute format is shown below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
48 for Acct-Output-Packets.
Length
6
Value
The Value field is four octets.
5.10. Acct-Terminate-Cause
Description
This attribute indicates how the session was terminated, and can only be present in Accounting-Request records where the Acct-Status-Type is set to Stop.
A summary of the Acct-Terminate-Cause attribute format is shown below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
49 for Acct-Terminate-Cause
Length
6
Value
The Value field is four octets, containing an integer specifying the cause of session termination, as follows:
| Value | Name |
|---|---|
| 1 | User Request |
| 2 | Lost Carrier |
| 3 | Lost Service |
| 4 | Idle Timeout |
| 5 | Session Timeout |
| 6 | Admin Reset |
| 7 | Admin Reboot |
| 8 | Port Error |
| 9 | NAS Error |
| 10 | NAS Request |
| 11 | NAS Reboot |
| 12 | Port Unneeded |
| 13 | Port Preempted |
| 14 | Port Suspended |
| 15 | Service Unavailable |
| 16 | Callback |
| 17 | User Error |
| 18 | Host Request |
The termination causes are as follows:
User Request — User requested termination of service, for example with LCP Terminate or by logging out.
Lost Carrier — DCD was dropped on the port.
Lost Service — Service can no longer be provided; for example, user's connection to a host was interrupted.
Idle Timeout — Idle timer expired.
Session Timeout — Maximum session length timer expired.
Admin Reset — Administrator reset the port or session.
Admin Reboot — Administrator is ending service on the NAS, for example prior to rebooting the NAS.
Port Error — NAS detected an error on the port which required ending the session.
NAS Error — NAS detected some error (other than on the port) which required ending the session.
NAS Request — NAS ended session for a non-error reason not otherwise listed here.
NAS Reboot — The NAS ended the session in order to reboot non-administratively ("crash").
Port Unneeded — NAS ended session because resource usage fell below low-water mark (for example, if a bandwidth-on-demand algorithm decided that the port was no longer needed).
Port Preempted — NAS ended session in order to allocate the port to a higher priority use.
Port Suspended — NAS ended session to suspend a virtual session.
Service Unavailable — NAS was unable to provide requested service.
Callback — NAS is terminating current session in order to perform callback for a new session.
User Error — Input from user is in error, causing termination of session.
Host Request — Login Host terminated session normally.
5.11. Acct-Multi-Session-Id
Description
This attribute is a unique Accounting ID to make it easy to link together multiple related sessions in a log file. Each session linked together would have a unique Acct-Session-Id but the same Acct-Multi-Session-Id. It is strongly recommended that the Acct-Multi-Session-Id contain UTF-8 encoded 10646 [7] characters.
A summary of the Acct-Session-Id attribute format is shown below. The fields are transmitted from left to right.
0 1 2
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | String ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
50 for Acct-Multi-Session-Id.
Length
= 3
String
The String field SHOULD contain UTF-8 encoded 10646 [7] characters.
5.12. Acct-Link-Count
Description
This attribute gives the count of links which are known to have been in a given multilink session at the time the accounting record is generated. The NAS MAY include the Acct-Link-Count attribute in any Accounting-Request which might have multiple links.
A summary of the Acct-Link-Count attribute format is show below. The fields are transmitted from left to right.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
51 for Acct-Link-Count.
Length
6
Value
The Value field is four octets, and contains the number of links seen so far in this Multilink Session.
It may be used to make it easier for an accounting server to know when it has all the records for a given Multilink session. When the number of Accounting-Requests received with Acct-Status-Type = Stop and the same Acct-Multi-Session-Id and unique Acct-Session-Id's equals the largest value of Acct-Link-Count seen in those Accounting-Requests, all Stop Accounting-Requests for that Multilink Session have been received.
An example showing 8 Accounting-Requests should make things clearer. For clarity only the relevant attributes are shown, but additional attributes containing accounting information will also be present in the Accounting-Request.
| Multi-Session-Id | Session-Id | Status-Type | Link-Count |
|---|---|---|---|
| "10" | "10" | Start | 1 |
| "10" | "11" | Start | 2 |
| "10" | "11" | Stop | 2 |
| "10" | "12" | Start | 3 |
| "10" | "13" | Start | 4 |
| "10" | "12" | Stop | 4 |
| "10" | "13" | Stop | 4 |
| "10" | "10" | Stop | 4 |
5.13. Table of Attributes
The following table provides a guide to which attributes may be found in Accounting-Request packets. No attributes should be found in Accounting-Response packets except Proxy-State and possibly Vendor-Specific.
| Count | Attribute |
|---|---|
| 0-1 | User-Name |
| 0 | User-Password |
| 0 | CHAP-Password |
| 0-1 | NAS-IP-Address [Note 1] |
| 0-1 | NAS-Port |
| 0-1 | Service-Type |
| 0-1 | Framed-Protocol |
| 0-1 | Framed-IP-Address |
| 0-1 | Framed-IP-Netmask |
| 0-1 | Framed-Routing |
| 0+ | Filter-Id |
| 0-1 | Framed-MTU |
| 0+ | Framed-Compression |
| 0+ | Login-IP-Host |
| 0-1 | Login-Service |
| 0-1 | Login-TCP-Port |
| 0 | Reply-Message |
| 0-1 | Callback-Number |
| 0-1 | Callback-Id |
| 0+ | Framed-Route |
| 0-1 | Framed-IPX-Network |
| 0 | State |
| 0+ | Class |
| 0+ | Vendor-Specific |
| 0-1 | Session-Timeout |
| 0-1 | Idle-Timeout |
| 0-1 | Termination-Action |
| 0-1 | Called-Station-Id |
| 0-1 | Calling-Station-Id |
| 0-1 | NAS-Identifier [Note 1] |
| 0+ | Proxy-State |
| 0-1 | Login-LAT-Service |
| 0-1 | Login-LAT-Node |
| 0-1 | Login-LAT-Group |
| 0-1 | Framed-AppleTalk-Link |
| 0-1 | Framed-AppleTalk-Network |
| 0-1 | Framed-AppleTalk-Zone |
| 1 | Acct-Status-Type |
| 0-1 | Acct-Delay-Time |
| 0-1 | Acct-Input-Octets |
| 0-1 | Acct-Output-Octets |
| 1 | Acct-Session-Id |
| 0-1 | Acct-Authentic |
| 0-1 | Acct-Session-Time |
| 0-1 | Acct-Input-Packets |
| 0-1 | Acct-Output-Packets |
| 0-1 | Acct-Terminate-Cause |
| 0+ | Acct-Multi-Session-Id |
| 0+ | Acct-Link-Count |
| 0 | CHAP-Challenge |
| 0-1 | NAS-Port-Type |
| 0-1 | Port-Limit |
| 0-1 | Login-LAT-Port |
[Note 1] An Accounting-Request MUST contain either a NAS-IP-Address or a NAS-Identifier (or both).
The following table defines the above table entries.
| Symbol | Meaning |
|---|---|
| 0 | This attribute MUST NOT be present |
| 0+ | Zero or more instances of this attribute MAY be present. |
| 0-1 | Zero or one instance of this attribute MAY be present. |
| 1 | Exactly one instance of this attribute MUST be present. |