eap Mailing List: Re: Issue 376: Proposed Resolution (Section 1)

[Bari, Farooq (farooq.bari]

Hi Bernard,

I would propose to replace the term "roaming user" with "user" in you
proposed changes as this problem can exist even when the user is not
roaming e.g. when multiple networks with different capabilities exist
with user's home operator at a geographic location. Is that change
acceptable?

BR,
 
Farooq Bari
farooq.bari [at] att.com
+1 425 580 5526
 
> -----Original Message-----
> From: Bernard Aboba [mailto:bernard_aboba [at] hotmail.com]
> Sent: Sunday, February 25, 2007 3:42 PM
> To: eap [at] frascone.com
> Subject: [eap] Issue 376: Proposed Resolution (Section 1)
> 
> In the next few messages, I will propose specific changes to address
Issue
> 376.  This message will concentrate on changes to the abstract and
Section
> 1.  Other messages will deal with other sections of the document.
> 
> Abstract
> 
>    The so called network discovery and selection problem affects
network
>    access, particularly in the presence of multiple available wireless
>    accesses and roaming.  This problem has been the subject of
>    discussions in various standards bodies.  This document summarizes
>    the discussion held about this problem in the Extensible
>    Authentication Protocol (EAP) working group at the IETF.  The
problem
>    is defined and divided into subproblems, and some constraints for
>    possible solutions are outlined.  The document also provides a
>    discussion of the limitations of certain classes of solution,
>    including some that have been previously defined.
> 
> Suggest changing to:
> 
>    When multiple access network are available, roaming
>    users may have difficulty in selecting which network
>    to connect to, and how to authenticate with that network.
>    This document defines the network discovery and
>    selection problem, dividing it into multiple sub-problems.
>    Some constraints on potential solutions are outlined, and
>    the limitations of several solutions (including existing ones)
>    are discussed.
> 
> 1. Introduction
> 
>    The network discovery and selection problem affects network access
>    and wireless access networks in particular.  Aspects of the problem
>    will appear when any of the following conditions are true:
> 
> [BA] Suggest changing to:
> 
>    When multiple access network are available, roaming
>    users may have difficulty in selecting which network
>    to connect to, and how to authenticate with that network.
>    The problem arises when any of the following conditions are
>    true:
> 
> [BA] The next few paragraphs state conditions under which the problem
> can occur, but don't clearly state what bad things will happen in
> each circumstance:
> 
>    o  There is more than one available network attachment point, and
the
>       different attachment points may have different characteristics
or
>       belong to different operators.  In the case of virtual
operators,
>       access network infrastructure including e.g. the access points
can
>       be shared by multiple operators.  In order to choose between the
>       network attachment points, it may be helpful to determine which
>       realms are supported and the capabilities access network
>       supporting those realms.  Otherwise, the mobile station might
>       frequently roam into networks that are not able to satisfy the
>       roaming connectivity needs or provide services the mobile
station
>       (and the subscriber) are seeking for.  This would of course
lower
>       the general quality of offered services.
> 
>    o  The user has multiple sets of credentials.  For instance, the
user
>       could have one set of credentials from a public service provider
>       and set from the user's employer.  In this case it may be
helpful
>       to provide additional information to enable the correct
credential
>       set to be determined.  Otherwise, it could happen that for
example
>       a network access authentication repeatedly fails because of
>       incorrectly selected and offered set of credentials.
> 
>    o  There is more than one way to provide roaming between the
visited
>       realm used for access and user's home realm, and service
>       parameters or pricing differs between them.  For instance, the
>       visited access realm could have both a direct relationship with
>       the home realm and an indirect relationship through a roaming
>       consortium.  In some scenarios, current AAA protocols may not be
>       able to route the requests to the home realm unaided, just based
>       on the domain in the given Network Access Identifier (NAI)
>       [RFC4282].  In addition, payload packets can get routed or
>       tunneled differently, based on the roaming relationship path in
>       use.  This may have an impact on the available services or their
>       pricing.
> 
> [BA] Suggest changing to:
> 
>    o  More than one network attachment point is available, and the
>       attachment points differ in capability or belong to different
>       operators.  In this case, a roaming user may have difficulty
>       determining which attachment points offering the desired
services
>       it can successfully authenticate to.  In order to choose between
>       multiple attachment points, it can be helpful to determine which
>       realms are supported and the capabilities that the networks
support
> 
>    o  The user has multiple sets of credentials.  In this case, the
>       user may not be able to determine which credentials to use with
>       which attachment point, or even whether any credentials it
>       possesses will allow it to authenticate successfully.  This
>       can result in multiple unsuccessful authentication attempts
>       for each attachment point, wasting valuable time and resulting
>       in user frustration.   For example, the user
>       could have one set of credentials from a public service provider
>       and set from an employer.  In order to choose between multiple
>       attachment points, it can be helpful to provide additional
>       information to enable the correct credentials to be determined.
> 
>    o  There are multiple potential roaming paths between the visited
>       realm and the user's home realm, and service parameters or
>       pricing differs between them.  In this case, the access network
>       may not be able to determine the roaming path that best matches
>       the user's preferences.  This can lead to the user being
>       charged more than necessary, or not obtaining the desired
>       services.  For example, the visited access realm could have
>       both a direct relationship with the home realm and an indirect
>       relationship through a roaming consortium.  Current AAA
protocols
>       may not be able to route the access request to the home AAA
sever
>       purely based on the realm within the Network Access Identifier
(NAI)
>       [RFC4282].  In addition, payload packets can be routed or
>       tunneled differently, based on the roaming relationship path.
>       This may have an impact on the available services or their
>       pricing.
> 
> [BA] The next paragraph could be cleaned up a bit:
> 
>    In Section 2 the network discovery and selection problem is defined
>    and divided into subproblems, and some design issues for possible
>    solutions are outlined in Section 3.  Section 4 gives the
conclusions
>    and some suggestions on how to proceed for the rest.  Appendix A
>    discusses existing mechanisms which help solve at least parts of
the
>    problem.  The terms "network" and "realm" have sometimes been used
>    interchangeably within the context of selection and discovery.  It
>    should be noted that a realm can be reachable from more than one
>    access network types and selection of a realm may not imply certain
>    network capabilities.
> 
> Suggest changing to:
> 
>    In Section 2 the network discovery and selection problem is defined
>    and divided into subproblems, and some potential solution
constraints
>    are outlined in Section 3.  Section 4 provides conclusions
>    and suggestions for future work.  Appendix A
>    discusses existing solutions to portions of the problem.
> 
> [BA] The following sentences belong in the terminology section:
> 
>    The terms "network" and "realm" have sometimes been used
>    interchangeably within the context of selection and discovery.  It
>    should be noted that a realm can be reachable from more than one
>    access network types and selection of a realm may not imply certain
>    network capabilities.
> 
> 
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