RFC 7155
Diameter Network Access Server Application
4.4. NAS Authorization AVPs
This section contains the authorization AVPs supported in the NAS Application. The Service-Type AVP SHOULD be present in all messages and, based on its value, additional AVPs defined in this section and Section 4.5 MAY be present. The following table gives the possible flag values for the session- level AVPs.
+----------+
| AVP Flag |
| Rules |
|----+-----|
|MUST| MUST|
Attribute Name Section Defined | | NOT|
-----------------------------------------|----+-----|
Service-Type 4.4.1 | M | V |
Callback-Number 4.4.2 | M | V |
Callback-Id 4.4.3 | M | V |
Idle-Timeout 4.4.4 | M | V |
Port-Limit 4.4.5 | M | V |
NAS-Filter-Rule 4.4.6 | M | V |
Filter-Id 4.4.7 | M | V |
Configuration-Token 4.4.8 | M | V |
QoS-Filter-Rule 4.4.9 | | |
Framed-Protocol 4.4.10.1 | M | V |
Framed-Routing 4.4.10.2 | M | V |
Framed-MTU 4.4.10.3 | M | V |
Framed-Compression 4.4.10.4 | M | V |
Framed-IP-Address 4.4.10.5.1 | M | V |
Framed-IP-Netmask 4.4.10.5.2 | M | V |
Framed-Route 4.4.10.5.3 | M | V |
Framed-Pool 4.4.10.5.4 | M | V |
Framed-Interface-Id 4.4.10.5.5 | M | V |
Framed-IPv6-Prefix 4.4.10.5.6 | M | V |
Framed-IPv6-Route 4.4.10.5.7 | M | V |
Framed-IPv6-Pool 4.4.10.5.8 | M | V |
Framed-IPX-Network 4.4.10.6.1 | M | V |
Framed-Appletalk-Link 4.4.10.7.1 | M | V |
Framed-Appletalk-Network 4.4.10.7.2 | M | V |
Framed-Appletalk-Zone 4.4.10.7.3 | M | V |
ARAP-Features 4.4.10.8.1 | M | V |
ARAP-Zone-Access 4.4.10.8.2 | M | V |
Login-IP-Host 4.4.11.1 | M | V |
Login-IPv6-Host 4.4.11.2 | M | V |
Login-Service 4.4.11.3 | M | V |
Login-TCP-Port 4.4.11.4.1 | M | V |
Login-LAT-Service 4.4.11.5.1 | M | V |
Login-LAT-Node 4.4.11.5.2 | M | V |
Login-LAT-Group 4.4.11.5.3 | M | V |
Login-LAT-Port 4.4.11.5.4 | M | V |
-----------------------------------------|----+-----|
4.4.1. Service-Type AVP
The Service-Type AVP (AVP Code 6) is of type Enumerated and contains the type of service the user has requested or the type of service to be provided. One such AVP MAY be present in an authentication and/or authorization request or response. A NAS is not required to implement all of these service types. It MUST treat unknown or unsupported Service-Type AVPs received in a response as a failure and end the session with a DIAMETER_INVALID_AVP_VALUE Result-Code. When used in a request, the Service-Type AVP SHOULD be considered a hint to the server that the NAS believes the user would prefer the kind of service indicated. The server is not required to honor the hint. Furthermore, if the service specified by the server is supported, but not compatible with the current mode of access, the NAS MUST fail to start the session. The NAS MUST also generate the appropriate error message(s). The complete list of defined values that the Service-Type AVP can take can be found in [RFC2865] and the relevant IANA registry [RADIUSAttrVals], but the following values require further qualification here: Login (1) The user should be connected to a host. The message MAY include additional AVPs as defined in Sections 4.4.11.4 or 4.4.11.5. Framed (2) A Framed Protocol, such as PPP or SLIP, should be started for the user. The message MAY include additional AVPs defined in Sections 4.4.10 or 4.5 for tunneling services. Callback Login (3) The user should be disconnected and called back, then connected to a host. The message MAY include additional AVPs defined in this section.
Callback Framed (4)
The user should be disconnected and called back, and then a
Framed Protocol, such as PPP or SLIP, should be started for the
user. The message MAY include additional AVPs defined in
Sections 4.4.10 or 4.5 for tunneling services.
4.4.2. Callback-Number AVP
The Callback-Number AVP (AVP Code 19) is of type UTF8String and
contains a dialing string to be used for callback, the format of
which is deployment specific. The Callback-Number AVP MAY be used in
an authentication and/or authorization request as a hint to the
server that a callback service is desired, but the server is not
required to honor the hint in the corresponding response.
Any further codification of this field's allowed usage range is
outside the scope of this specification.
4.4.3. Callback-Id AVP
The Callback-Id AVP (AVP Code 20) is of type UTF8String and contains
the name of a place to be called, to be interpreted by the NAS. This
AVP MAY be present in an authentication and/or authorization
response.
This AVP is not roaming-friendly as it assumes that the Callback-Id
is configured on the NAS. Using the Callback-Number AVP
(Section 4.4.2) is therefore RECOMMENDED.
4.4.4. Idle-Timeout AVP
The Idle-Timeout AVP (AVP Code 28) is of type Unsigned32 and sets the
maximum number of consecutive seconds of idle connection allowable to
the user before termination of the session or before a prompt is
issued. The default is none or system specific.
4.4.5. Port-Limit AVP
The Port-Limit AVP (AVP Code 62) is of type Unsigned32 and sets the
maximum number of ports the NAS provides to the user. It MAY be used
in an authentication and/or authorization request as a hint to the
server that multilink PPP [RFC1990] service is desired, but the
server is not required to honor the hint in the corresponding
response.
4.4.6. NAS-Filter-Rule AVP
The NAS-Filter-Rule AVP (AVP Code 400) is of type IPFilterRule and provides filter rules that need to be configured on the NAS for the user. One or more of these AVPs MAY be present in an authorization response.4.4.7. Filter-Id AVP
The Filter-Id AVP (AVP Code 11) is of type UTF8String and contains the name of the filter list for this user. It is intended to be human readable. Zero or more Filter-Id AVPs MAY be sent in an authorization answer message. Identifying a filter list by name allows the filter to be used on different NASes without regard to filter-list implementation details. However, this AVP is not roaming-friendly, as filter naming differs from one service provider to another. In environments where backward compatibility with RADIUS is not required, it is RECOMMENDED that the NAS-Filter-Rule AVP (Section 4.4.6) be used instead.4.4.8. Configuration-Token AVP
The Configuration-Token AVP (AVP Code 78) is of type OctetString and is sent by a Diameter server to a Diameter Proxy Agent in an AA- Answer command to indicate a type of user profile to be used. It should not be sent to a Diameter client (NAS). The format of the Data field of this AVP is site specific.4.4.9. QoS-Filter-Rule AVP
The QoS-Filter-Rule AVP (AVP Code 407) is of type QoSFilterRule (Section 4.1.1) and provides QoS filter rules that need to be configured on the NAS for the user. One or more such AVPs MAY be present in an authorization response. The use of this AVP is NOT RECOMMENDED; the AVPs defined by [RFC5777] SHOULD be used instead. The following options are defined for the QoSFilterRule filters:
DSCP <color>
If action is set to tag (Section 4.1.1), this option MUST be
included in the rule.
Color values are defined in [RFC2474]. Exact matching of DSCP
values is required (no masks or ranges).
metering <rate> <color_under> <color_over>
The metering option provides Assured Forwarding, as defined in
[RFC2597]. and MUST be present if the action is set to meter
(Section 4.1.1) The rate option is the throughput, in bits per
second, used by the access device to mark packets. Traffic
over the rate is marked with the color_over codepoint, and
traffic under the rate is marked with the color_under
codepoint. The color_under and color_over options contain the
drop preferences and MUST conform to the recommended codepoint
keywords described in [RFC2597] (e.g., AF13).
The metering option also supports the strict limit on traffic
required by Expedited Forwarding, as defined in [RFC3246]. The
color_over option may contain the keyword "drop" to prevent
forwarding of traffic that exceeds the rate parameter.
4.4.10. Framed Access Authorization AVPs
This section lists the authorization AVPs necessary to support framed
access, such as PPP and SLIP. AVPs defined in this section MAY be
present in a message if the Service-Type AVP was set to "Framed" or
"Callback Framed".
4.4.10.1. Framed-Protocol AVP
The Framed-Protocol AVP (AVP Code 7) is of type Enumerated and
contains the framing to be used for framed access. This AVP MAY be
present in both requests and responses. The supported values are
listed in [RADIUSAttrVals].
4.4.10.2. Framed-Routing AVP
The Framed-Routing AVP (AVP Code 10) is of type Enumerated and
contains the routing method for the user when the user is a router to
a network. This AVP SHOULD only be present in authorization
responses. The supported values are listed in [RADIUSAttrVals].
4.4.10.3. Framed-MTU AVP
The Framed-MTU AVP (AVP Code 12) is of type Unsigned32 and contains the Maximum Transmission Unit (MTU) to be configured for the user, when it is not negotiated by some other means (such as PPP). This AVP SHOULD only be present in authorization responses. The MTU value MUST be in the range from 64 to 65535.4.4.10.4. Framed-Compression AVP
The Framed-Compression AVP (AVP Code 13) is of type Enumerated and contains the compression protocol to be used for the link. It MAY be used in an authorization request as a hint to the server that a specific compression type is desired, but the server is not required to honor the hint in the corresponding response. More than one compression protocol AVP MAY be sent. The NAS is responsible for applying the proper compression protocol to the appropriate link traffic. The supported values are listed in [RADIUSAttrVals].4.4.10.5. IP Access Authorization AVPs
The AVPs defined in this section are used when the user requests, or is being granted, access service to IP.4.4.10.5.1. Framed-IP-Address AVP
The Framed-IP-Address AVP (AVP Code 8) [RFC2865] is of type OctetString and contains an IPv4 address of the type specified in the attribute value to be configured for the user. It MAY be used in an authorization request as a hint to the server that a specific address is desired, but the server is not required to honor the hint in the corresponding response. Two values have special significance: 0xFFFFFFFF and 0xFFFFFFFE. The value 0xFFFFFFFF indicates that the NAS should allow the user to select an address (i.e., negotiated). The value 0xFFFFFFFE indicates that the NAS should select an address for the user (e.g., assigned from a pool of addresses kept by the NAS).4.4.10.5.2. Framed-IP-Netmask AVP
The Framed-IP-Netmask AVP (AVP Code 9) is of type OctetString and contains the four octets of the IPv4 netmask to be configured for the user when the user is a router to a network. It MAY be used in an authorization request as a hint to the server that a specific netmask
is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST be present in a response if the request included this AVP with a value of 0xFFFFFFFF.4.4.10.5.3. Framed-Route AVP
The Framed-Route AVP (AVP Code 22) is of type UTF8String and contains the 7-bit US-ASCII routing information to be configured for the user on the NAS. Zero or more of these AVPs MAY be present in an authorization response. The string MUST contain a destination prefix in dotted quad form optionally followed by a slash and a decimal-length specifier stating how many high-order bits of the prefix should be used. This is followed by a space, a gateway address in dotted quad form, a space, and one or more metrics separated by spaces; for example, "192.0.2.0/24 192.0.2.1 1" The length specifier may be omitted, in which case it should default to 8 bits for class A prefixes, 16 bits for class B prefixes, and 24 bits for class C prefixes; for example, "192.0.2.0 192.0.2.1 1" Whenever the gateway address is specified as "0.0.0.0", the IP address of the user SHOULD be used as the gateway address.4.4.10.5.4. Framed-Pool AVP
The Framed-Pool AVP (AVP Code 88) is of type OctetString and contains the name of an assigned address pool that SHOULD be used to assign an address for the user. If a NAS does not support multiple address pools, the NAS SHOULD ignore this AVP. Address pools are usually used for IP addresses but can be used for other protocols if the NAS supports pools for those protocols. Although specified as type OctetString for compatibility with RADIUS [RFC2869], the encoding of the Data field SHOULD also conform to the rules for the UTF8String Data Format.4.4.10.5.5. Framed-Interface-Id AVP
The Framed-Interface-Id AVP (AVP Code 96) is of type Unsigned64 and contains the IPv6 interface identifier to be configured for the user. It MAY be used in authorization requests as a hint to the server that a specific interface identifier is desired, but the server is not required to honor the hint in the corresponding response.
4.4.10.5.6. Framed-IPv6-Prefix AVP
The Framed-IPv6-Prefix AVP (AVP Code 97) is of type OctetString and contains the IPv6 prefix to be configured for the user. One or more AVPs MAY be used in authorization requests as a hint to the server that specific IPv6 prefixes are desired, but the server is not required to honor the hint in the corresponding response.4.4.10.5.7. Framed-IPv6-Route AVP
The Framed-IPv6-Route AVP (AVP Code 99) is of type UTF8String and contains the US-ASCII routing information to be configured for the user on the NAS. Zero or more of these AVPs MAY be present in an authorization response. The string MUST contain an IPv6 address prefix followed by a slash and a decimal-length specifier stating how many high-order bits of the prefix should be used. This is followed by a space, a gateway address in hexadecimal notation, a space, and one or more metrics separated by spaces; for example, "2001:db8::/32 2001:db8:106:a00:20ff:fe99:a998 1" Whenever the gateway address is the IPv6 unspecified address, the IP address of the user SHOULD be used as the gateway address, such as in: "2001:db8::/32 :: 1"4.4.10.5.8. Framed-IPv6-Pool AVP
The Framed-IPv6-Pool AVP (AVP Code 100) is of type OctetString and contains the name of an assigned pool that SHOULD be used to assign an IPv6 prefix for the user. If the access device does not support multiple prefix pools, it MUST ignore this AVP. Although specified as type OctetString for compatibility with RADIUS [RFC3162], the encoding of the Data field SHOULD also conform to the rules for the UTF8String Data Format.4.4.10.6. IPX Access AVPs
The AVPs defined in this section are used when the user requests, or is being granted, access to an IPX network service [IPX].
4.4.10.6.1. Framed-IPX-Network AVP
The Framed-IPX-Network AVP (AVP Code 23) is of type Unsigned32 and contains the IPX Network number to be configured for the user. It MAY be used in an authorization request as a hint to the server that a specific address is desired, but the server is not required to honor the hint in the corresponding response. Two addresses have special significance: 0xFFFFFFFF and 0xFFFFFFFE. The value 0xFFFFFFFF indicates that the NAS should allow the user to select an address (i.e., Negotiated). The value 0xFFFFFFFE indicates that the NAS should select an address for the user (e.g., assign it from a pool of one or more IPX networks kept by the NAS).4.4.10.7. AppleTalk Network Access AVPs
The AVPs defined in this section are used when the user requests, or is being granted, access to an AppleTalk network [AppleTalk].4.4.10.7.1. Framed-Appletalk-Link AVP
The Framed-Appletalk-Link AVP (AVP Code 37) is of type Unsigned32 and contains the AppleTalk network number that should be used for the serial link to the user, which is another AppleTalk router. This AVP MUST only be present in an authorization response and is never used when the user is not another router. Despite the size of the field, values range from 0 to 65,535. The special value of 0 indicates an unnumbered serial link. A value of 1 to 65,535 means that the serial line between the NAS and the user should be assigned that value as an AppleTalk network number.4.4.10.7.2. Framed-Appletalk-Network AVP
The Framed-Appletalk-Network AVP (AVP Code 38) is of type Unsigned32 and contains the AppleTalk network number that the NAS should probe to allocate an AppleTalk node for the user. This AVP MUST only be present in an authorization response and is never used when the user is not another router. Multiple instances of this AVP indicate that the NAS may probe, using any of the network numbers specified. Despite the size of the field, values range from 0 to 65,535. The special value 0 indicates that the NAS should assign a network for the user, using its default cable range. A value between 1 and 65,535 (inclusive) indicates to the AppleTalk network that the NAS should probe to find an address for the user.
4.4.10.7.3. Framed-Appletalk-Zone AVP
The Framed-Appletalk-Zone AVP (AVP Code 39) is of type OctetString and contains the AppleTalk Default Zone to be used for this user. This AVP MUST only be present in an authorization response. Multiple instances of this AVP in the same message are not allowed. The codification of this field's allowed range is outside the scope of this specification.4.4.10.8. AppleTalk Remote Access AVPs
The AVPs defined in this section are used when the user requests, or is being granted, access to the AppleTalk network via the AppleTalk Remote Access Protocol [ARAP]. They are only present if the Framed- Protocol AVP (Section 4.4.10.1) is set to ARAP. Section 2.2 of RFC 2869 describes the operational use of these attributes.4.4.10.8.1. ARAP-Features AVP
The ARAP-Features AVP (AVP Code 71) is of type OctetString and MAY be present in the AA-Accept message if the Framed-Protocol AVP is set to the value of ARAP. See RFC 2869 for more information about the format of this AVP.4.4.10.8.2. ARAP-Zone-Access AVP
The ARAP-Zone-Access AVP (AVP Code 72) is of type Enumerated and MAY be present in the AA-Accept message if the Framed-Protocol AVP is set to the value of ARAP. The supported values are listed in [RADIUSAttrVals] and defined in [RFC2869].4.4.11. Non-Framed Access Authorization AVPs
This section contains the authorization AVPs that are needed to support terminal server functionality. AVPs defined in this section MAY be present in a message if the Service-Type AVP was set to "Login" or "Callback Login".4.4.11.1. Login-IP-Host AVP
The Login-IP-Host AVP (AVP Code 14) [RFC2865] is of type OctetString and contains the IPv4 address of a host with which to connect the user when the Login-Service AVP is included. It MAY be used in an
AA-Request command as a hint to the Diameter server that a specific host is desired, but the Diameter server is not required to honor the hint in the AA-Answer. Two addresses have special significance: all ones and 0. The value of all ones indicates that the NAS SHOULD allow the user to select an address. The value 0 indicates that the NAS SHOULD select a host to connect the user to.4.4.11.2. Login-IPv6-Host AVP
The Login-IPv6-Host AVP (AVP Code 98) [RFC3162] is of type OctetString and contains the IPv6 address of a host with which to connect the user when the Login-Service AVP is included. It MAY be used in an AA-Request command as a hint to the Diameter server that a specific host is desired, but the Diameter server is not required to honor the hint in the AA-Answer. Two addresses have special significance, 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF and 0. The value 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF indicates that the NAS SHOULD allow the user to select an address. The value 0 indicates that the NAS SHOULD select a host to connect the user to.4.4.11.3. Login-Service AVP
The Login-Service AVP (AVP Code 15) is of type Enumerated and contains the service that should be used to connect the user to the login host. This AVP SHOULD only be present in authorization responses. The supported values are listed in RFC 2869.4.4.11.4. TCP Services
The AVP described in the following section MAY be present if the Login-Service AVP is set to Telnet, Rlogin, TCP Clear, or TCP Clear Quiet.4.4.11.4.1. Login-TCP-Port AVP
The Login-TCP-Port AVP (AVP Code 16) is of type Unsigned32 and contains the TCP port with which the user is to be connected when the Login-Service AVP is also present. This AVP SHOULD only be present in authorization responses. The value MUST NOT be greater than 65,535.
4.4.11.5. LAT Services
The AVPs described in this section MAY be present if the Login- Service AVP is set to LAT [LAT].4.4.11.5.1. Login-LAT-Service AVP
The Login-LAT-Service AVP (AVP Code 34) is of type OctetString and contains the system with which the user is to be connected by LAT. It MAY be used in an authorization request as a hint to the server that a specific service is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST only be present in the response if the Login-Service AVP states that LAT is desired. Administrators use this service attribute when dealing with clustered systems. In these environments, several different time-sharing hosts share the same resources (disks, printers, etc.), and administrators often configure each host to offer access (service) to each of the shared resources. In this case, each host in the cluster advertises its services through LAT broadcasts. Sophisticated users often know which service providers (machines) are faster and tend to use a node name when initiating a LAT connection. Some administrators want particular users to use certain machines as a primitive form of load balancing (although LAT knows how to do load balancing itself). The String field contains the identity of the LAT service to use. The LAT Architecture allows this string to contain $ (dollar), - (hyphen), . (period), _ (underscore), numerics, upper- and lower-case alphabetics, and the ISO Latin-1 character set extension [ISO.8859-1.1987]. All LAT string comparisons are case insensitive.4.4.11.5.2. Login-LAT-Node AVP
The Login-LAT-Node AVP (AVP Code 35) is of type OctetString and contains the Node with which the user is to be automatically connected by LAT. It MAY be used in an authorization request as a hint to the server that a specific LAT node is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST only be present in a response if the Login- Service-Type AVP is set to LAT.
The String field contains the identity of the LAT service to use. The LAT Architecture allows this string to contain $ (dollar), - (hyphen), . (period), _ (underscore), numerics, upper- and lower-case alphabetics, and the ISO Latin-1 character set extension [ISO.8859-1.1987]. All LAT string comparisons are case insensitive.4.4.11.5.3. Login-LAT-Group AVP
The Login-LAT-Group AVP (AVP Code 36) is of type OctetString and contains a string identifying the LAT group codes this user is authorized to use. It MAY be used in an authorization request as a hint to the server that a specific group is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST only be present in a response if the Login-Service-Type AVP is set to LAT. LAT supports 256 different group codes, which LAT uses as a form of access rights. LAT encodes the group codes as a 256-bit bitmap. Administrators can assign one or more of the group code bits at the LAT service provider; it will only accept LAT connections that have these group codes set in the bitmap. The administrators assign a bitmap of authorized group codes to each user. LAT gets these from the operating system and uses them in its requests to the service providers. The codification of the range of allowed usage of this field is outside the scope of this specification.4.4.11.5.4. Login-LAT-Port AVP
The Login-LAT-Port AVP (AVP Code 63) is of type OctetString and contains the port with which the user is to be connected by LAT. It MAY be used in an authorization request as a hint to the server that a specific port is desired, but the server is not required to honor the hint in the corresponding response. This AVP MUST only be present in a response if the Login-Service-Type AVP is set to LAT. The String field contains the identity of the LAT service to use. The LAT Architecture allows this string to contain $ (dollar), - (hyphen), . (period), _ (underscore), numerics, upper- and lower-case alphabetics, and the ISO Latin-1 character set extension [ISO.8859-1.1987]. All LAT string comparisons are case insensitive.
4.5. NAS Tunneling AVPs
Some NASes support compulsory tunnel services in which the incoming connection data is conveyed by an encapsulation method to a gateway elsewhere in the network. This is typically transparent to the service user, and the tunnel characteristics may be described by the remote Authentication, Authorization, and Accounting server, based on the user's authorization information. Several tunnel characteristics may be returned, and the NAS implementation may choose one. See [RFC2868] and [RFC2867] for further information. The following table gives the possible flag values for the session- level AVPs and specifies whether the AVP MAY be encrypted. +----------+ | AVP Flag | | Rules | |----+-----| |MUST| MUST| Attribute Name Section Defined | | NOT | -----------------------------------------|----+-----| Tunneling 4.5.1 | M | V | Tunnel-Type 4.5.2 | M | V | Tunnel-Medium-Type 4.5.3 | M | V | Tunnel-Client-Endpoint 4.5.4 | M | V | Tunnel-Server-Endpoint 4.5.5 | M | V | Tunnel-Password 4.5.6 | M | V | Tunnel-Private-Group-Id 4.5.7 | M | V | Tunnel-Assignment-Id 4.5.8 | M | V | Tunnel-Preference 4.5.9 | M | V | Tunnel-Client-Auth-Id 4.5.10 | M | V | Tunnel-Server-Auth-Id 4.5.11 | M | V | -----------------------------------------|----+-----|4.5.1. Tunneling AVP
The Tunneling AVP (AVP Code 401) is of type Grouped and contains the following AVPs, used to describe a compulsory tunnel service [RFC2868] [RFC2867]. Its data field has the following ABNF grammar:
Tunneling ::= < AVP Header: 401 >
{ Tunnel-Type }
{ Tunnel-Medium-Type }
{ Tunnel-Client-Endpoint }
{ Tunnel-Server-Endpoint }
[ Tunnel-Preference ]
[ Tunnel-Client-Auth-Id ]
[ Tunnel-Server-Auth-Id ]
[ Tunnel-Assignment-Id ]
[ Tunnel-Password ]
[ Tunnel-Private-Group-Id ]
4.5.2. Tunnel-Type AVP
The Tunnel-Type AVP (AVP Code 64) is of type Enumerated and contains
the tunneling protocol(s) to be used (in the case of a tunnel
initiator) or in use (in the case of a tunnel terminator). It MAY be
used in an authorization request as a hint to the server that a
specific tunnel type is desired, but the server is not required to
honor the hint in the corresponding response.
The Tunnel-Type AVP SHOULD also be included in ACR messages.
A tunnel initiator is not required to implement any of these tunnel
types. If a tunnel initiator receives a response that contains only
unknown or unsupported tunnel types, the tunnel initiator MUST behave
as though a response were received with the Result-Code indicating a
failure.
The supported values are listed in [RADIUSAttrVals].
4.5.3. Tunnel-Medium-Type AVP
The Tunnel-Medium-Type AVP (AVP Code 65) is of type Enumerated and
contains the transport medium to use when creating a tunnel for
protocols (such as L2TP [RFC3931]) that can operate over multiple
transports. It MAY be used in an authorization request as a hint to
the server that a specific medium is desired, but the server is not
required to honor the hint in the corresponding response.
The supported values are listed in [RADIUSAttrVals].
4.5.4. Tunnel-Client-Endpoint AVP
The Tunnel-Client-Endpoint AVP (AVP Code 66) is of type UTF8String
and contains the address of the initiator end of the tunnel. It MAY
be used in an authorization request as a hint to the server that a
specific endpoint is desired, but the server is not required to honor
the hint in the corresponding response. This AVP SHOULD be included in the corresponding ACR messages, in which case it indicates the address from which the tunnel was initiated. This AVP, along with the Tunnel-Server-Endpoint (Section 4.5.5) and Session-Id AVPs ([RFC6733], Section 8.8), can be used to provide a globally unique means to identify a tunnel for accounting and auditing purposes. If the value of the Tunnel-Medium-Type AVP (Section 4.5.3) is IPv4 (1), then this string is either the fully qualified domain name (FQDN) of the tunnel client machine or a "dotted-decimal" IP address. Implementations MUST support the dotted-decimal format and SHOULD support the FQDN format for IP addresses. If Tunnel-Medium-Type is IPv6 (2), then this string is either the FQDN of the tunnel client machine or a text representation of the address in either the preferred or alternate form [RFC3516]. Conforming implementations MUST support the preferred form and SHOULD support both the alternate text form and the FQDN format for IPv6 addresses. If Tunnel-Medium-Type is neither IPv4 nor IPv6, then this string is a tag referring to configuration data local to the Diameter client that describes the interface or medium-specific client address to use. Note that this application handles Internationalized Domain Names (IDNs) in the same way as the Diameter Base protocol (see Appendix D of RFC 6733 for details).4.5.5. Tunnel-Server-Endpoint AVP
The Tunnel-Server-Endpoint AVP (AVP Code 67) is of type UTF8String and contains the address of the server end of the tunnel. It MAY be used in an authorization request as a hint to the server that a specific endpoint is desired, but the server is not required to honor the hint in the corresponding response. This AVP SHOULD be included in the corresponding ACR messages, in which case it indicates the address from which the tunnel was initiated. This AVP, along with the Tunnel-Client-Endpoint (Section 4.5.4) and Session-Id AVP ([RFC6733], Section 8.8), can be used to provide a globally unique means to identify a tunnel for accounting and auditing purposes. If Tunnel-Medium-Type is IPv4 (1), then this string is either the fully qualified domain name (FQDN) of the tunnel server machine, or a "dotted-decimal" IP address. Implementations MUST support the dotted-decimal format and SHOULD support the FQDN format for IP addresses.
If Tunnel-Medium-Type is IPv6 (2), then this string is either the FQDN of the tunnel server machine, or a text representation of the address in either the preferred or alternate form [RFC3516]. Implementations MUST support the preferred form and SHOULD support both the alternate text form and the FQDN format for IPv6 addresses. If Tunnel-Medium-Type is not IPv4 or IPv6, this string is a tag referring to configuration data local to the Diameter client that describes the interface or medium-specific server address to use. Note that this application handles IDNs in the same way as the Diameter base protocol (see Appendix D of RFC 6733 for details).4.5.6. Tunnel-Password AVP
The Tunnel-Password AVP (AVP Code 69) is of type OctetString and may contain a password to be used to authenticate to a remote server. The Tunnel-Password AVP SHOULD NOT be used in untrusted proxy environments without encrypting it by using end-to-end security techniques.4.5.7. Tunnel-Private-Group-Id AVP
The Tunnel-Private-Group-Id AVP (AVP Code 81) is of type OctetString and contains the group Id for a particular tunneled session. The Tunnel-Private-Group-Id AVP MAY be included in an authorization request if the tunnel initiator can predetermine the group resulting from a particular connection. It SHOULD be included in the authorization response if this tunnel session is to be treated as belonging to a particular private group. Private groups may be used to associate a tunneled session with a particular group of users. For example, it MAY be used to facilitate routing of unregistered IP addresses through a particular interface. This AVP SHOULD be included in the ACR messages that pertain to the tunneled session.4.5.8. Tunnel-Assignment-Id AVP
The Tunnel-Assignment-Id AVP (AVP Code 82) is of type OctetString and is used to indicate to the tunnel initiator the particular tunnel to which a session is to be assigned. Some tunneling protocols, such as PPTP [RFC2637] and L2TP [RFC3931], allow for sessions between the same two tunnel endpoints to be multiplexed over the same tunnel and also for a given session to use its own dedicated tunnel. This attribute provides a mechanism for Diameter to inform the tunnel initiator (for example, a LAC) whether to assign the session to a
multiplexed tunnel or to a separate tunnel. Furthermore, it allows
for sessions sharing multiplexed tunnels to be assigned to different
multiplexed tunnels.
A particular tunneling implementation may assign differing
characteristics to particular tunnels. For example, different
tunnels may be assigned different QoS parameters. Such tunnels may
be used to carry either individual or multiple sessions. The Tunnel-
Assignment-Id attribute thus allows the Diameter server to indicate
that a particular session is to be assigned to a tunnel providing an
appropriate level of service. It is expected that any QoS-related
Diameter tunneling attributes defined in the future accompanying this
one will be associated by the tunnel initiator with the Id given by
this attribute. In the meantime, any semantic given to a particular
Id string is a matter left to local configuration in the tunnel
initiator.
The Tunnel-Assignment-Id AVP is of significance only to Diameter and
the tunnel initiator. The Id it specifies is only intended to be of
local use to Diameter and the tunnel initiator. The Id assigned by
the tunnel initiator is not conveyed to the tunnel peer.
This attribute MAY be included in authorization responses. The
tunnel initiator receiving this attribute MAY choose to ignore it and
to assign the session to an arbitrary multiplexed or non-multiplexed
tunnel between the desired endpoints. This AVP SHOULD also be
included in the Accounting-Request messages pertaining to the
tunneled session.
If a tunnel initiator supports the Tunnel-Assignment-Id AVP, then it
should assign a session to a tunnel in the following manner:
o If this AVP is present and a tunnel exists between the specified
endpoints with the specified Id, then the session should be
assigned to that tunnel.
o If this AVP is present and no tunnel exists between the specified
endpoints with the specified Id, then a new tunnel should be
established for the session and the specified Id should be
associated with the new tunnel.
o If this AVP is not present, then the session is assigned to an
unnamed tunnel. If an unnamed tunnel does not yet exist between
the specified endpoints, then it is established and used for this
session and for subsequent ones established without the Tunnel-
Assignment-Id attribute. A tunnel initiator MUST NOT assign a
session for which a Tunnel-Assignment-Id AVP was not specified to
a named tunnel (i.e., one that was initiated by a session
specifying this AVP).
Note that the same Id may be used to name different tunnels if these
tunnels are between different endpoints.
4.5.9. Tunnel-Preference AVP
The Tunnel-Preference AVP (AVP Code 83) is of type Unsigned32 and is
used to identify the relative preference assigned to each tunnel when
more than one set of tunneling AVPs is returned within separate
grouped AVPs. It MAY be used in an authorization request as a hint
to the server that a specific preference is desired, but the server
is not required to honor the hint in the corresponding response.
For example, suppose that AVPs describing two tunnels are returned by
the server, one with a tunnel type of PPTP and the other with a
tunnel type of L2TP. If the tunnel initiator supports only one of
the tunnel types returned, it will initiate a tunnel of that type.
If, however, it supports both tunnel protocols, it SHOULD use the
value of the Tunnel-Preference AVP to decide which tunnel should be
started. The tunnel with the lowest numerical value in the Value
field of this AVP SHOULD be given the highest preference. The values
assigned to two or more instances of the Tunnel-Preference AVP within
a given authorization response MAY be identical. In this case, the
tunnel initiator SHOULD use locally configured metrics to decide
which set of AVPs to use.
4.5.10. Tunnel-Client-Auth-Id AVP
The Tunnel-Client-Auth-Id AVP (AVP Code 90) is of type UTF8String and
specifies the 7-bit US-ASCII name used by the tunnel initiator during
the authentication phase of tunnel establishment. It MAY be used in
an authorization request as a hint to the server that a specific
preference is desired, but the server is not required to honor the
hint in the corresponding response. This AVP MUST be present in the
authorization response if an authentication name other than the
default is desired. This AVP SHOULD be included in the ACR messages
pertaining to the tunneled session.
4.5.11. Tunnel-Server-Auth-Id AVP
The Tunnel-Server-Auth-Id AVP (AVP Code 91) is of type UTF8String and
specifies the 7-bit US-ASCII name used by the tunnel terminator
during the authentication phase of tunnel establishment. It MAY be
used in an authorization request as a hint to the server that a
specific preference is desired, but the server is not required to
honor the hint in the corresponding response. This AVP MUST be present in the authorization response if an authentication name other than the default is desired. This AVP SHOULD be included in the ACR messages pertaining to the tunneled session.4.6. NAS Accounting AVPs
Applications implementing this specification use Diameter Accounting (as defined in [RFC6733]) and the AVPs in the following section. Service-specific AVP usage is defined in the tables in Section 5. If accounting is active, Accounting Request (ACR) messages SHOULD be sent after the completion of any Authentication or Authorization transaction and at the end of a session. The value of the Accounting-Record-Type AVP [RFC6733] indicates the type of event. All other AVPs identify the session and provide additional information relevant to the event. The successful completion of the first Authentication or Authorization transaction SHOULD cause a START_RECORD to be sent. If additional Authentications or Authorizations occur in later transactions, the first exchange should generate a START_RECORD, and the latter an INTERIM_RECORD. For a given session, there MUST only be one set of matching START and STOP records, with any number of INTERIM_RECORDS in between, or one EVENT_RECORD indicating the reason a session wasn't started. The following table gives the possible flag values for the session- level AVPs and specifies whether the AVP MAY be encrypted.
+----------+
| AVP Flag |
| Rules |
|----+-----|
Section |MUST| MUST|
Attribute Name Defined | | NOT|
-----------------------------------------|----+-----|
Accounting-Input-Octets 4.6.1 | M | V |
Accounting-Output-Octets 4.6.2 | M | V |
Accounting-Input-Packets 4.6.3 | M | V |
Accounting-Output-Packets 4.6.4 | M | V |
Acct-Session-Time 4.6.5 | M | V |
Acct-Authentic 4.6.6 | M | V |
Accounting-Auth-Method 4.6.7 | M | V |
Acct-Delay-Time 4.6.8 | M | V |
Acct-Link-Count 4.6.9 | M | V |
Acct-Tunnel-Connection 4.6.10 | M | V |
Acct-Tunnel-Packets-Lost 4.6.11 | M | V |
-----------------------------------------|----+-----|
4.6.1. Accounting-Input-Octets AVP
The Accounting-Input-Octets AVP (AVP Code 363) is of type Unsigned64
and contains the number of octets received from the user.
For NAS usage, this AVP indicates how many octets have been received
from the port in the course of this session. It can only be present
in ACR messages with an Accounting-Record-Type [RFC6733] of
INTERIM_RECORD or STOP_RECORD.
4.6.2. Accounting-Output-Octets AVP
The Accounting-Output-Octets AVP (AVP Code 364) is of type Unsigned64
and contains the number of octets sent to the user.
For NAS usage, this AVP indicates how many octets have been sent to
the port in the course of this session. It can only be present in
ACR messages with an Accounting-Record-Type of INTERIM_RECORD or
STOP_RECORD.
4.6.3. Accounting-Input-Packets AVP
The Accounting-Input-Packets (AVP Code 365) is of type Unsigned64 and
contains the number of packets received from the user.
For NAS usage, this AVP indicates how many packets have been received from the port over the course of a session being provided to a Framed User. It can only be present in ACR messages with an Accounting- Record-Type of INTERIM_RECORD or STOP_RECORD.4.6.4. Accounting-Output-Packets AVP
The Accounting-Output-Packets (AVP Code 366) is of type Unsigned64 and contains the number of IP packets sent to the user. For NAS usage, this AVP indicates how many packets have been sent to the port over the course of a session being provided to a Framed User. It can only be present in ACR messages with an Accounting- Record-Type of INTERIM_RECORD or STOP_RECORD.4.6.5. Acct-Session-Time AVP
The Acct-Session-Time AVP (AVP Code 46) is of type Unsigned32 and indicates the length of the current session in seconds. It can only be present in ACR messages with an Accounting-Record-Type of INTERIM_RECORD or STOP_RECORD.4.6.6. Acct-Authentic AVP
The Acct-Authentic AVP (AVP Code 45) is of type Enumerated and specifies how the user was authenticated. The supported values are listed in [RADIUSAttrVals].4.6.7. Accounting-Auth-Method AVP
The Accounting-Auth-Method AVP (AVP Code 406) is of type Enumerated. A NAS MAY include this AVP in an Accounting-Request message to indicate the method used to authenticate the user. (Note that this AVP is semantically equivalent, and the supported values are identical, to the Microsoft MS-Acct-Auth-Type vendor-specific RADIUS attribute [RFC2548]).4.6.8. Acct-Delay-Time AVP
The Acct-Delay-Time AVP (AVP Code 41) is of type Unsigned32 and indicates the number of seconds the Diameter client has been trying to send the Accounting-Request (ACR). The accounting server may subtract this value from the time when the ACR arrives at the server to calculate the approximate time of the event that caused the ACR to be generated.
This AVP is not used for retransmissions at the transport level (TCP or SCTP). Rather, it may be used when an ACR command cannot be transmitted because there is no appropriate peer to transmit it to or it was rejected because it could not be delivered. In these cases, the command MAY be buffered and transmitted later, when an appropriate peer-connection is available or after sufficient time has passed that the destination-host may be reachable and operational. If the ACR is re-sent in this way, the Acct-Delay-Time AVP SHOULD be included. The value of this AVP indicates the number of seconds that elapsed between the time of the first attempt at transmission and the current attempt.4.6.9. Acct-Link-Count AVP
The Acct-Link-Count AVP (AVP Code 51) is of type Unsigned32 and indicates the total number of links that have been active (current or closed) in a given multilink session at the time the accounting record is generated. This AVP MAY be included in Accounting-Request AVPs for any session that may be part of a multilink service. The Acct-Link-Count AVP may be used to make it easier for an accounting server to know when it has all the records for a given multilink service. When the number of Accounting-Request AVPs received with Accounting-Record-Type = STOP_RECORD and with the same Acct-Multi-Session-Id and unique Session-Id AVPs equals the largest value of Acct-Link-Count seen in those Accounting-Request AVPs, all STOP_RECORD Accounting-Request AVPs for that multilink service have been received. The following example, showing eight Accounting-Request AVPs, illustrates how the Acct-Link-Count AVP is used. In the table below, only the relevant AVPs are shown, although additional AVPs containing accounting information will be present in the Accounting-Requests AVPs.
Acct-Multi- Accounting- Acct-
Session-Id Session-Id Record-Type Link-Count
--------------------------------------------------------
"...10" "...10" START_RECORD 1
"...10" "...11" START_RECORD 2
"...10" "...11" STOP_RECORD 2
"...10" "...12" START_RECORD 3
"...10" "...13" START_RECORD 4
"...10" "...12" STOP_RECORD 4
"...10" "...13" STOP_RECORD 4
"...10" "...10" STOP_RECORD 4
4.6.10. Acct-Tunnel-Connection AVP
The Acct-Tunnel-Connection AVP (AVP Code 68) is of type OctetString
and contains the identifier assigned to the tunnel session. This
AVP, along with the Tunnel-Client-Endpoint (Section 4.5.4) and
Tunnel-Server-Endpoint (Section 4.5.5) AVPs, may be used to provide a
means to uniquely identify a tunnel session for auditing purposes.
The format of the identifier in this AVP depends upon the value of
the Tunnel-Type AVP (Section 4.5.2). For example, to identify an
L2TP tunnel connection fully, the L2TP Tunnel Id and Call Id might be
encoded in this field. The exact encoding of this field is
implementation dependent.
4.6.11. Acct-Tunnel-Packets-Lost AVP
The Acct-Tunnel-Packets-Lost AVP (AVP Code 86) is of type Unsigned32
and contains the number of packets lost on a given tunnel.
(page 55 continued on part 4)
