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Re: Data types in Diameter
>>>>> David T Perkins writes:
David> I just recently read the definition of Diameter. The document
David> is
David> (http://www.ietf.org/internet-drafts/draft-ietf-aaa-diameter-05.txt)
David> It defines the following data types: OctetString Address (IPv4
David> or IPv6 address) Integer32 Integer64, Unsigned32 Unsigned64
David> Float32 Float64 Float128 Grouped (which is a sequence)
David> Now, if we could get them to add OID, and develop an common
David> plan for floating point, then our data types would match, and
David> inter-operability would be improved. Does anyone know why all
David> these float types are specified in Diameter?
They are going to remove Address from the base types and it will be
defined as a derived type called IPAddress in the next revision. The
float type definitions match the IEEE floating point standard and is
consistent with the SMIng definitions. Diameter lacks an OID as nobody
managed to convince AAA folks this is needed. If you feel strongly
about this, then _now_ is the time to file an issue on the AAA mailing
list.
David> Also, Diameter sends messages that consist of a list of
David> "attribute-value pairs" (AVPs). Such a list is an SNMP
David> varBindList, and an AVP is a varBind. The Diameter attributes
David> are identified by one number if standards-track (and two
David> numbers if vendor defined) instead a sequence of numbers (an
David> OID) as found in SNMP. However, I couldn't figure out
David> multi-instanced attributes were specified. (Does someone know?)
David> It might be a good thing to have instances identified like in
David> SNMP.
Diameter is different from SNMP as they do not have the notion of a
name for object instances. Diameter is more a message passing protocol
and AVPs only exist and have semantics in the message they are part
of. (At least this is how I understand it.) Hence, an AVP is not
really the same as an SNMP varbind since SNMP varbinds contain a
name of a variable.
Hope this helps.
/js
--
Juergen Schoenwaelder Technical University Braunschweig
<schoenw@ibr.cs.tu-bs.de> Dept. Operating Systems & Computer Networks
Phone: +49 531 391 3289 Bueltenweg 74/75, 38106 Braunschweig, Germany
Fax: +49 531 391 5936 <URL:http://www.ibr.cs.tu-bs.de/~schoenw/>