3Com Baseline 2928 PWR Plus User Manual page 401

2) The Identifier field (1-byte long) is for matching request packets and response packets and
detecting retransmitted request packets. The request and response packets of the same type have
the same identifier.
3) The Length field (2-byte long) indicates the length of the entire packet, including the Code,
Identifier, Length, Authenticator, and Attribute fields. The value of the field is in the range 20 to
4096. Bytes beyond the length are considered the padding and are neglected upon reception. If the
length of a received packet is less than that indicated by the Length field, the packet is dropped.
4) The Authenticator field (16-byte long) is used to authenticate replies from the RADIUS server, and
is also used in the password hiding algorithm. There are two kinds of authenticators: request
authenticator and response authenticator.
5) The Attribute field, with a variable length, carries the specific authentication, authorization, and
accounting information for defining configuration details of the request or response. This field is
represented in triplets of Type, Length, and Value.
Type: One byte, in the range 1 to 255. It indicates the type of the attribute. Commonly used
attributes for RADIUS authentication, authorization and accounting are listed in
Length: One byte for indicating the length of the attribute in bytes, including the Type, Length, and
Value fields.
Value: Value of the attribute, up to 253 bytes. Its format and content depend on the Type and
Length fields.
Table 1-2 RADIUS attributes
No.
1 User-Name
2 User-Password
3 CHAP-Password
4 NAS-IP-Address
5 NAS-Port
6 Service-Type
7 Framed-Protocol
8 Framed-IP-Address
9 Framed-IP-Netmask
10 Framed-Routing
11 Filter-ID
12 Framed-MTU
13 Framed-Compression
14 Login-IP-Host
15 Login-Service
16 Login-TCP-Port
17 (unassigned)
18 Reply_Message
19 Callback-Number
20 Callback-ID
Attribute
1-4
No.
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
52 Acct-Input-Gigawords
53 Acct-Output-Gigawords
54 (unassigned)
55 Event-Timestamp
56-59 (unassigned)
60 CHAP-Challenge
61 NAS-Port-Type
62 Port-Limit
63 Login-LAT-Port
64 Tunnel-Type
65 Tunnel-Medium-Type
66 Tunnel-Client-Endpoint
67 Tunnel-Server-Endpoint
Table 1-2.
Attribute