Network Working Group V. Mammoliti

Network Working Group V. Mammoliti
Request for Comments: 4679 G. Zorn
Category: Informational Cisco Systems
P. Arberg
Redback Networks, Inc.
R. Rennison
ECI Telecom
September 2006

DSL Forum Vendor-Specific RADIUS Attributes

Status of this Memo

This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2006).

IESG Note

This RFC is not a candidate for any level of Internet Standard. The
IETF disclaims any knowledge of the fitness of this RFC for any
purpose and in particular notes that the decision to publish is not
based on IETF review for such things as security, congestion control,
or inappropriate interaction with deployed protocols. The RFC Editor
has chosen to publish this document at its discretion. Readers of
this document should exercise caution in evaluating its value for
implementation and deployment. See RFC 3932 for more information.

Abstract

This document describes the set of Remote Authentication Dial-In User
Service Vendor-Specific Attributes (RADIUS VSAs) defined by the DSL
Forum.

These attributes are designed to transport Digital Subscriber Line
(DSL) information that is not supported by the standard RADIUS
attribute set. It is expected that this document will be updated if
and when the DSL Forum defines additional vendor-specific attributes,
since its primary purpose is to provide a reference for DSL equipment
vendors wishing to interoperate with other vendors' products.

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RFC 4679 DSL Forum RADIUS VSA September 2006

Table of Contents

1. Introduction ....................................................3
2. Terminology .....................................................3
2.1. Requirements Language ......................................3
2.2. Technical Terms and Acronyms ...............................3
3. Attributes ......................................................5
3.1. DSL Forum RADIUS VSA Definition ............................5
3.2. DSL Forum Vendor Specific Sub-Attribute Encoding ...........6
3.3. Sub-attribute Definitions ..................................6
3.3.1. Agent-Circuit-Id ....................................6
3.3.2. Agent-Remote-Id .....................................8
3.3.3. Actual-Data-Rate-Upstream ...........................9
3.3.4. Actual-Data-Rate-Downstream .........................9
3.3.5. Minimum-Data-Rate-Upstream .........................10
3.3.6. Minimum-Data-Rate-Downstream .......................11
3.3.7. Attainable-Data-Rate-Upstream ......................11
3.3.8. Attainable-Data-Rate-Downstream ....................12
3.3.9. Maximum-Data-Rate-Upstream .........................13
3.3.10. Maximum-Data-Rate-Downstream ......................13
3.3.11. Minimum-Data-Rate-Upstream-Low-Power ..............14
3.3.12. Minimum-Data-Rate-Downstream-Low-Power ............15
3.3.13. Maximum-Interleaving-Delay-Upstream ...............16
3.3.14. Actual-Interleaving-Delay-Upstream ................16
3.3.15. Maximum-Interleaving-Delay-Downstream .............17
3.3.16. Actual-Interleaving-Delay-Downstream ..............18
3.3.17. Access-Loop-Encapsulation .........................19
3.3.18. IWF-Session .......................................20
4. Table of Attributes ............................................21
5. Security Considerations ........................................21
6. References .....................................................22
6.1. Normative References ......................................22
6.2. Informative References ....................................22

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RFC 4679 DSL Forum RADIUS VSA September 2006

1. Introduction

The DSL Forum has created additional RADIUS [RFC2865] [RFC2866]
vendor-specific attributes to carry DSL line identification and
characterization information. This information is forwarded from the
Access Node/DSLAM to the BRAS via Vendor-Specific PPPoE Tags
[RFC2516], DHCP Relay Options [RFC3046], and Vendor-Specific
Information Suboptions [RFC4243]. This document describes the
subscriber line identification and characterization information and
its mapping to RADIUS VSAs by the BRAS.

The information acquired may be used to provide authentication and
accounting functionality. It may also be collected and used for
management and troubleshooting purposes.

2. Terminology

The following sections define the usage and meaning of certain
specialized terms in the context of this document.

2.1. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].

2.2. Technical Terms and Acronyms

AAL5
ATM Adaption Layer 5 [ITU.I363-5.1996]

Access Node/DSLAM
The Access Node/DSLAM is a DSL signal terminator that contains a
minimum of one Ethernet interface that serves as its northbound
interface into which it aggregates traffic from several
Asynchronous Transfer Mode (ATM)-based (subscriber ports) or
Ethernet-based southbound interfaces.

BNG
Broadband Network Gateway. A BNG is an IP edge router where
bandwidth and QoS policies are applied; the functions performed by
a BRAS are a superset of those performed by a BNG.

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RFC 4679 DSL Forum RADIUS VSA September 2006

BRAS
Broadband Remote Access Server. A BRAS is a BNG and is the
aggregation point for the subscriber traffic. It provides
aggregation capabilities (e.g., IP, PPP, Ethernet) between the
access network and the core network. Beyond its aggregation
function, the BRAS is also an injection point for policy
management and IP QoS in the access network.

DSL
Digital Subscriber Line. DSL is a technology that allows digital
data transmission over wires in the local telephone network.

DSLAM
Digital Subscriber Line Access Multiplexer. DSLAM is a device
that terminates DSL subscriber lines. The data is aggregated and
forwarded to ATM- or Ethernet-based aggregation networks.

FCS
Frame Check Sequence. The FCS is a checksum added to an Ethernet
frame for error detection/correction purposes.

IPoA
IP over ATM

IWF
Interworking Function. The set of functions required for
interconnecting two networks of different technologies (e.g., ATM
and Ethernet). IWF is utilized to enable the carriage of PPP over
ATM (PPPoA) traffic over PPPoE.

LLC
Logical Link Control

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RFC 4679 DSL Forum RADIUS VSA September 2006

3. Attributes

The following subsections describe the Attributes defined by this
document. These Attributes MAY be transmitted in one or more RADIUS
Attributes of type Vendor-Specific [RFC2865]. More than one
attribute MAY be transmitted in a single Vendor-Specific Attribute;
if this is done, the attributes SHOULD be packed as a sequence of
Vendor-Type/Vendor-Length/Value triples following the initial Type,
Length, and Vendor-Id fields.

3.1. DSL Forum RADIUS VSA Definition

Description

This Attribute functions as a "container", encapsulating one or
more vendor-specific sub-attributes; the encoding follows the
recommendations in [RFC2865].

A summary of the generic DSL Forum VSA 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 | Vendor-Id
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Vendor-Id (cont) | Sub-Attribute(s)...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Type

26 for Vendor-Specific

Length

This field MUST be set equal to the sum of the Vendor-Length
fields of the sub-attributes contained in the Vendor-Specific
Attribute, plus six (Type + Length + Vendor-Id).

Vendor-Id

This field MUST be set to decimal 3561, the enterprise number
assigned to the ADSL Forum [IANA].

Sub-Attributes

This field MUST contain one or more DSL Forum Vendor-Specific
sub-attributes, as specified below.

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3.2. DSL Forum Vendor Specific Sub-Attribute Encoding

A summary of the sub-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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

The Vendor-Type field is one octet in length and contains the
sub-attribute type, as assigned by the DSL Forum.

Vendor-Length

The Vendor-Length field is one octet and indicates the length of
the entire sub-attribute, including the Vendor-Type,
Vendor-Length, and Value fields.

Value

The Value field is zero or more octets and contains information
specific to the sub-attribute. The format and length of the Value
field is determined by the Vendor-Type and Vendor-Length fields.
The format of the value field is one of 2 data types, string or
integer [RFC2865].

3.3. Sub-attribute Definitions

The following sub-sections define the DSL Forum vendor-specific sub-
attributes.

3.3.1. Agent-Circuit-Id

Description

This Attribute contains information describing the subscriber
agent circuit identifier corresponding to the logical access loop
port of the Access Node/DSLAM from which a subscriber's requests
are initiated. It MAY be present in both Access-Request and
Accounting-Request packets.

A summary of the Agent-Circuit-Id Attribute format is shown below.
The fields are transmitted from left to right.

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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | String...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

1 for Agent-Circuit-Id

Vendor-Length

<= 65

String

The String field contains information about the Access-Node to
which the subscriber is attached, along with an identifier for the
subscriber's DSL port on that Access-Node.

The exact syntax of the string is implementation dependent;
however, a typical practice is to subdivide it into two or more
space-separated components, one to identify the Access-Node and
another the subscriber line on that node, with perhaps an
indication of whether that line is Ethernet or ATM. Example
formats for this string are shown below.

"Access-Node-Identifier atm slot/port:vpi.vci"
(when ATM/DSL is used)

"Access-Node-Identifier eth slot/port[:vlan-id]"
(when Ethernet/DSL is used)

An example showing the slot and port field encoding is given
below:

"[Relay-identifier] atm 3/0:100.33"
(slot = 3, port = 0, vpi = 100, vci = 33)

The Access-Node-Identifier is a unique ASCII string that does not
include 'space' characters. The syntax of the slot and port
fields reflects typical practices currently in place. The slot
identifier does not exceed 6 characters in length, and the port
identifier does not exceed 3 characters in length using a '\' as a
delimiter.

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RFC 4679 DSL Forum RADIUS VSA September 2006

The exact manner in which slots are identified is Access
Node/DSLAM implementation dependent. The vpi, vci, and vlan-id
fields (when applicable) are related to a given access loop
(U-interface).

3.3.2. Agent-Remote-Id

Description

The Agent-Remote-Id Attribute contains an operator-specific,
statically configured string that uniquely identifies the
subscriber on the associated access loop of the Access Node/DSLAM.

In a typical subscriber environment, multiple attributes can be
used to identify the user, among others: Username (for example, as
defined on a PPP client); Agent-Circuit-Id (a static, pre-defined
string sent from the Access Node/DSLAM); Agent-Remote-Id (an
operator-defined string configured on and sent by the Access
Node/DSLAM).

This Attribute MAY be included in both Access-Request and
Accounting-Request packets.

A summary of the Agent-Remote-Id 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | String...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

2 for Agent-Remote-Id

Vendor-Length

<= 65

String

This value of this field is entirely open to the service
provider's discretion. For example, it MAY contain a subscriber
billing identifier or telephone number.

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3.3.3. Actual-Data-Rate-Upstream

Description

This Attribute contains the actual upstream train rate of a
subscriber's synchronized DSL link. It MAY be included in both
Access-Request and Accounting-Request packets.

A summary of the Actual-Data-Rate-Upstream 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

129 (0x81) for Actual-Data-Rate-Upstream

Vendor-Length

6

Value

This field contains a 4-byte unsigned integer, indicating the
subscriber's actual data rate upstream of a synchronized DSL link.
The rate is coded in bits per second.

3.3.4. Actual-Data-Rate-Downstream

Description

This Attribute contains the actual downstream train rate of a
subscriber's synchronized DSL link. It MAY be included in both
Access-Request and Accounting-Request packets.

A summary of the Actual-Data-Rate-Downstream Attribute format is
shown below. The fields are transmitted from left to right.

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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

130 (0x82) for Actual-Data-Rate-Downstream

Vendor-Length

6

Value

This field contains a 4-byte unsigned integer, indicating the
subscriber's actual data rate downstream of a synchronized DSL
link. The rate is coded in bits per second.

3.3.5. Minimum-Data-Rate-Upstream

Description

This Attribute contains the subscriber's operator-configured
minimum upstream data rate. It MAY be included in Accounting-
Request packets.

A summary of the Minimum-Data-Rate-Upstream 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

131 (0x83) for Minimum-Data-Rate-Upstream

Vendor-Length

6

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RFC 4679 DSL Forum RADIUS VSA September 2006

Value

This field contains a 4-byte unsigned integer, indicating the
subscriber's minimum upstream data rate (as configured by the
operator). The rate is coded in bits per second.

3.3.6. Minimum-Data-Rate-Downstream

Description

This Attribute contains the subscriber's operator-configured
minimum downstream data rate. It MAY be included in Accounting-
Request packets.

A summary of the Minimum-Data-Rate-Downstream 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

132 (0x84) for Minimum-Data-Rate-Downstream

Vendor-Length

6

Value

This field contains a 4-byte unsigned integer, indicating the
subscriber's minimum downstream data rate (as configured by the
operator). The rate is coded in bits per second.

3.3.7. Attainable-Data-Rate-Upstream

Description

This Attribute contains the subscriber's attainable upstream data
rate. It MAY be included in Accounting-Request packets.

A summary of the Attainable-Data-Rate-Upstream Attribute format is
shown below. The fields are transmitted from left to right.

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RFC 4679 DSL Forum RADIUS VSA September 2006

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

133 (0x85) for Attainable-Data-Rate-Upstream

Vendor-Length

6

Value

This field contains a 4-byte unsigned integer, indicating the
subscriber's actual DSL attainable upstream data rate. The rate
is coded in bits per second.

3.3.8. Attainable-Data-Rate-Downstream

Description

This Attribute contains the subscriber's attainable downstream
data rate. It MAY be included in Accounting-Request packets.

A summary of the Attainable-Data-Rate-Downstream 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

134 (0x86) for Attainable-Data-Rate-Downstream

Vendor-Length

6

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Value

This field contains a 4-byte unsigned integer, indicating the
subscriber's actual DSL attainable downstream data rate. The rate
is coded in bits per second.

3.3.9. Maximum-Data-Rate-Upstream

Description

This Attribute contains the subscriber's maximum upstream data
rate, as configured by the operator. It MAY be included in
Accounting-Request packets.

A summary of the Maximum-Data-Rate-Upstream 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

135 (0x87) for Maximum-Data-Rate-Upstream

Vendor-Length

6

Value

This field is a 4-byte unsigned integer, indicating the numeric
value of the subscriber's DSL maximum upstream data rate. The
rate is coded in bits per second.

3.3.10. Maximum-Data-Rate-Downstream

Description

This Attribute contains the subscriber's maximum downstream data
rate, as configured by the operator. It MAY be included in
Accounting-Request packets.

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A summary of the Maximum-Data-Rate-Downstream 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

136 (0x88) for Maximum-Data-Rate-Downstream

Vendor-Length

6

Value

This field is a 4-byte unsigned integer, indicating the numeric
value of the subscriber's DSL maximum downstream data rate. The
rate is coded in bits per second.

3.3.11. Minimum-Data-Rate-Upstream-Low-Power

Description

This Attribute contains the subscriber's minimum upstream data
rate in low power state, as configured by the operator. It MAY be
included in Accounting-Request packets.

A summary of the Minimum-Data-Rate-Upstream-Low-Power 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

137 (0x89) for Minimum-Data-Rate-Upstream-Low-Power

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Vendor-Length

6

Value

This field is a 4-byte unsigned integer, indicating the numeric
value of the subscriber's DSL minimum upstream data rate when in
low power state (L1/L2). The rate is coded in bits per second.

3.3.12. Minimum-Data-Rate-Downstream-Low-Power

Description

This Attribute contains the subscriber's minimum downstream data
rate in low power state, as configured by the operator. It MAY be
included in Accounting-Request packets.

A summary of the Minimum-Data-Rate-Downstream-Low-Power 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

138 (0x8A) for Minimum-Data-Rate-Downstream-Low-Power

Vendor-Length

6

Value

This field is a 4-byte unsigned integer, indicating the numeric
value of the subscriber's DSL minimum downstream data rate. The
rate is coded in bits per second.

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3.3.13. Maximum-Interleaving-Delay-Upstream

Description

This Attribute contains the subscriber's maximum one-way upstream
interleaving delay, as configured by the operator. It MAY be
included in Accounting-Request packets.

A summary of the Maximum-Interleaving-Delay-Upstream 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

139 (0x8B) for Maximum-Interleaving-Delay-Upstream

Vendor-Length

6

Value

This field is a 4-byte unsigned integer, indicating the numeric
value in milliseconds of the subscriber's DSL maximum one-way
upstream interleaving delay.

3.3.14. Actual-Interleaving-Delay-Upstream

Description

This Attribute contains the subscriber's actual one-way upstream
interleaving delay. It MAY be included in Accounting-Request
packets.

A summary of the Actual-Interleaving-Delay-Upstream Attribute format
is shown below. The fields are transmitted from left to right.

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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

140 (0x8C) for Actual-Interleaving-Delay-Upstream

Vendor-Length

6

Value

This field is a 4-byte unsigned integer, indicating the numeric
value in milliseconds of the subscriber's DSL actual upstream
interleaving delay.

3.3.15. Maximum-Interleaving-Delay-Downstream

Description

This Attribute contains the subscriber's maximum one-way
downstream interleaving delay, as configured by the operator. It
MAY be included in Accounting-Request packets.

A summary of the Maximum-Interleaving-Delay-Downstream 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

141 (0x8D) for Maximum-Interleaving-Delay-Downstream

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Vendor-Length

6

Value

This field is a 4-byte unsigned integer, indicating the numeric
value in milliseconds of the subscriber's DSL maximum one-way
downstream interleaving delay.

3.3.16. Actual-Interleaving-Delay-Downstream

Description

This Attribute contains the subscriber's actual one-way downstream
interleaving delay. It MAY be included in Accounting-Request
packets.

A summary of the Actual-Interleaving-Delay-Downstream 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

142 (0x8E) for Actual-Interleaving-Delay-Downstream

Vendor-Length

6

Value

This field is a 4-byte unsigned integer, indicating the numeric
value in milliseconds of the subscriber's DSL actual downstream
interleaving delay.

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3.3.17. Access-Loop-Encapsulation

Description

This Attribute describes the encapsulation(s) used by the
subscriber on the DSL access loop. It MAY be present in both
Access-Request and Accounting-Request packets.

A summary of the Access-Loop-Encapsulation 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length | Value
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Value (cont'd) |
+-+-+-+-+-+-+-+-+

Vendor-Type

144 (0x90) for Access-Loop-Encapsulation

Vendor-Length

5

Value

This field is a string 3 bytes in length, logically divided into
three 1-byte sub-fields as shown in the following diagram:

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Link | Encaps 1 | Encaps 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Valid values for the sub-fields are as follows:

Data Link

0x01 AAL5
0x02 Ethernet

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RFC 4679 DSL Forum RADIUS VSA September 2006

Encaps 1

0x00 NA - Not Available
0x01 Untagged Ethernet
0x02 Single-Tagged Ethernet

Encaps 2

0x00 NA - Not Available
0x01 PPPoA LLC
0x02 PPPoA Null
0x03 IPoA LLC
0x04 IPoA Null
0x05 Ethernet over AAL5 LLC with FCS
0x06 Ethernet over AAL5 LLC without FCS
0x07 Ethernet over AAL5 Null with FCS
0x08 Ethernet over AAL5 Null without FCS

3.3.18. IWF-Session

Description

The presence of this Attribute indicates that the IWF has been
performed with respect to the subscriber's session; note that no
data field is necessary. It MAY be included in both Access-
Request and Accounting-Request packets.

A summary of the IWF-Session Attribute format is shown below. The
fields are transmitted from left to right.

0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor-Type | Vendor-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Vendor-Type

254 (0xFE) for IWF-Session

Vendor-Length

2

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4. Table of Attributes

The following table provides a guide to which attributes may be found
in which kinds of packets, and in what quantity; note that since none
of the DSL Forum VSAs may be present in the Access-Accept, Access-
Reject or Access-Challenge packets, those columns have been omitted
from the table.

Request Acct-Request # Attribute
0-1 0-1 1 Agent-Circuit-Id
0-1 0-1 2 Agent-Remote-Id
0-1 0-1 129 Actual-Data-Rate-Upstream
0-1 0-1 130 Actual-Data-Rate-Downstream
0 0-1 131 Minimum-Data-Rate-Upstream
0 0-1 132 Minimum-Data-Rate-Downstream
0 0-1 133 Attainable-Data-Rate-Upstream
0 0-1 134 Attainable-Data-Rate-Downstream
0 0-1 135 Maximum-Data-Rate-Upstream
0 0-1 136 Maximum-Data-Rate-Downstream
0 0-1 137 Minimum-Data-Rate-Upstream-Low-Power
0 0-1 138 Minimum-Data-Rate-Downstream-Low-Power
0 0-1 139 Maximum-Interleaving-Delay-Upstream
0 0-1 140 Actual-Interleaving-Delay-Upstream
0 0-1 141 Maximum-Interleaving-Delay-Downstream
0 0-1 142 Actual-Interleaving-Delay-Downstream
0-1 0-1 144 Access-Loop-Encapsulation
0-1 0-1 254 IWF-Session

The following table defines the meaning of the above table entries.

0 This Attribute MUST NOT be present in packet.

0-1 Zero or one instances of this Attribute MAY be present in
packet.

5. Security Considerations

The security of these Attributes relies on an implied trust
relationship between the Access Node/DSLAM and the BRAS. The
identifiers that are inserted by the Access Node/DSLAM are
unconditionally trusted; the BRAS does not perform any validity check
on the information received. These Attributes are intended to be
used in environments in which the network infrastructure (the Access
Node/DSLAM, the BRAS, and the entire network in which those two
devices reside) is trusted and secure.

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RFC 4679 DSL Forum RADIUS VSA September 2006

As used in this document, the word "trusted" implies that
unauthorized traffic cannot enter the network except through secured
and trusted devices and that all devices internal to the network are
secure and trusted. Careful consideration should be given to the
potential security vulnerabilities that are present in this model
before deploying this option in actual networks.

The Attributes described in this document neither increase nor
decrease the security of the RADIUS protocol. For discussions of
various RADIUS vulnerabilities, see [RFC2607], [RFC3579], [RFC3162],
and [RFC3580].

6. References

6.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)",
RFC 2865, June 2000.

[RFC2866] Rigney, C., "RADIUS Accounting", RFC 2866, June 2000.

6.2. Informative References

[IANA] Internet Assigned Numbers Authority, "PRIVATE ENTERPRISE
NUMBERS", January 2006,
<http://www.iana.org/assignments/enterprise-numbers>.

[ITU.I363-5.1996]
International Telecommunications Union, "B-ISDN ATM
Adaptation Layer Specification: Type 5 AAL", ITU-T
Recommendation I.363.5, August 1996.

[RFC2516] Mamakos, L., Lidl, K., Evarts, J., Carrel, D., Simone, D.,
and R. Wheeler, "A Method for Transmitting PPP Over
Ethernet (PPPoE)", RFC 2516, February 1999.

[RFC2607] Aboba, B. and J. Vollbrecht, "Proxy Chaining and Policy
Implementation in Roaming", RFC 2607, June 1999.

[RFC3046] Patrick, M., "DHCP Relay Agent Information Option",
RFC 3046, January 2001.

[RFC3162] Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6",
RFC 3162, August 2001.

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RFC 4679 DSL Forum RADIUS VSA September 2006

[RFC3579] Aboba, B. and P. Calhoun, "RADIUS (Remote Authentication
Dial In User Service) Support For Extensible
Authentication Protocol (EAP)", RFC 3579, September 2003.

[RFC3580] Congdon, P., Aboba, B., Smith, A., Zorn, G., and J. Roese,
"IEEE 802.1X Remote Authentication Dial In User Service
(RADIUS) Usage Guidelines", RFC 3580, September 2003.

[RFC4243] Stapp, M., Johnson, R., and T. Palaniappan, "Vendor-
Specific Information Suboption for the Dynamic Host
Configuration Protocol (DHCP) Relay Agent Option",
RFC 4243, December 2005.

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RFC 4679 DSL Forum RADIUS VSA September 2006

Authors' Addresses

Vince Mammoliti
Cisco Systems
181 Bay Street, Suite 3400
Toronto, ON M5J 2T3
Canada

EMail: [email protected]

Glen Zorn
Cisco Systems
2901 Third Avenue, Suite 600
SEA1/5/
Seattle, WA 98121
USA

Phone: +1 (425) 344 8113
EMail: [email protected]

Peter Arberg
Redback Networks, Inc.
300 Holger Way
San Jose, CA 95134
USA

EMail: [email protected]

Robert Rennison
ECI Telecom
Omega Corporate Center
1300 Omega Drive
Pittsburgh, PA 15205
USA

EMail: [email protected]

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RFC 4679 DSL Forum RADIUS VSA September 2006

Full Copyright Statement

Copyright (C) The Internet Society (2006).

This document is subject to the rights, licenses and restrictions
contained in BCP 78 and at www.rfc-editor.org/copyright.html, and
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