eap Mailing List: Section 2.4 Clarification

Issue: Section 2.4 Clarification
Submitter name: Bernard Aboba
Submitter email address: aboba [at] internaut.com
Date Submitted: May 23, 2007
Reference:
Document: NETSEL-07
Comment type: Editorial
Priority: S
Section: 2.4
Rationale/Explanation of issue:

In reading through Section 2.4, it is not clear to me why the capabilities described are relevant or why the client cannot obtain them using existing mechanisms.  Some clarification is needed.  My suggestion is to rewrite Section 2.4 as follows:

"2.4.  Network Capability Discovery

   Network capability discovery focuses on discovery of 
   the services offered by networks, not just the capabilities 
   of individual points of attachment.  By acquiring additional
   information on access network characteristics, it is possible
   for users to make a more informed access decision.  
   These characteristics may include: 

   o  Roaming relationships between the access network provider and
      other network providers and associated costs.  Where the
      network access client is not preconfigured with an 
      identity and credentials corresponding to a local access
      network, it will need to be able to determine whether 
      one or more home realms are reachable from an access network
      so that successful authentication can be possible. 

   o  EAP authentication methods.  While the EAP authentication
      methods supported by a home realm can only be determined by
      contacting the home AAA server, it is possible that the 
      local realm will also support one or more EAP methods. 
      For example, a user may be able to utilize EAP-SIM to 
      authenticate to the access network directly, rather than 
      having to authenticate to the home network. 

   o  End-to-end quality of service capability.  While local
      quality of services capabilities are typically advertised
      by the access network (e.g. support for WMM), the availability
      of end-to-end QoS services may not be advertised. 

   o  Service parameters, such as the existence of middleboxes or
      firewalls.  If the network access client is not made aware
      of the Internet access that it will receive on connecting to
      a point of attachment, it is possible that the user may not
      be able to access the desired services. 

   Reference [IEEE.11-04-0624] classifies the possible steps at which
   IEEE 802.11 networks can acquire this information:

   o  Pre-association
   o  Post-association (or pre-authentication)
   o  Post-authentication

   In the interest of minimizing connectivity delays, all of 
   the information required for network selection (including both
   access network capabilities and global characteristics) needs to 
   be provided prior to authentication.  

   By the time authentication occurs, the node has
   typically selected the access network, the NAI to be used to
   authenticate, as well as the point of attachment.  Should it learn
   information during the authentication process that would cause it to
   revise one or more of those decisions, the node will need to select a
   new network, point of attachment, and/or identity, and then go
   through the authentication process all over again.  Such a process is
   likely to be both time consuming and unreliable."

Section 2.4 Clarification	<– Date –> <– Thread –>
From: Bernard Aboba (bernard_abobahotmail.com)
Date: Wed, 23 May 2007 22:21:15 -0700 (PDT)

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