Subject: [eap] Issue 142 suggestion: syntax for network info hint in Type-Data field of Identity-Request

From: [email-masked] (Lortz, Victor)
Date: Mon, 28 Jul 2003 07:36:06 -0700

In Issue 142, Bernard has suggested that specification of the Type-Data field data of Identity-Request after the nul character should include:
 
a) An ABNF describing the grammar for the parameters and values;
b) IANA considerations for allocation of parameters and values.

Here is a suggestion for dealing with points a) and b).

Suppose we use XML syntax instead of the previously proposed syntax for this data.  IANA considerations can  be dealt with using the XML namespace mechanism.  Here is an example:

display-string\0<?xml><NetInfo xmlns="urn:ietf.org:EAP:Netinfo" networkid="SomeSSID" nasid="SomeNASName"  portid="123" />

The schema associated with urn:ietf.org:EAP:Netinfo would define the attributes networkid, nasid, portid,  and whatever else might be appropriate.  The leading <?xml> is not strictly necessary, but it might be useful to help avoid confusion with existing practice that uses comma-separated attribute=value syntax.

One advantage of this approach is that vendor or domain-specific extensions can easily be added without requiring additional IANA requests.  For example,

display-string\0<?xml><NetInfo xmlns="urn:ietf.org:EAP:Netinfo" xmlns:gsm="urn:3gpp.org:wlan-info:1"  networkid="SomeSSID" nasid="SomeNASName" portid="123" gsm:VPLMNS="123456 123654 111222" />

To simplify parsing, it might be preferable that the schema restrict the NetInfo element to have only attributes, as shown in these examples (no child elements).   Besides the parsing simplifications that this restriction would provide, attributes are also more compact than elements (no need for a trailing </element>  tag).  

Regards,
Vic Lortz
Intel Corporation