Subject: [NSIS] An NSIS requirement with backing scenario

From: [email-masked]
Date: Tue, 12 Mar 2002 10:54:44 -0500

Hi:
 
I would like to place the following requirement on table for discussion in WG. I have also provided a scenario below that motivates such explicit requirement. I would like to know if WG deems this as an important issue.
 
"QoS signaling protocol MUST interwork with AAA for QoS authorization and accounting purposes".
 
Scenario:
-----------
 
A and B are connected to the Internet on the two sides of the globe. A places call to B, and (say during SIP transactions) intimates to B that A will pay for the call. Paying for the call also means paying for QoS of the corresponding packet transport. B accepts A's proposal. The call happens to be of bidirectional traffic type. 
 
A sends signal to its access network N_A asking it to give certain QoS to packet stream from A -> B. A is a subscribed customer of N_A, so there are no apparent difficulties for N_A in checking A's credentials and in billing A. Also, network N_A may then take appropriate means to guarantee end-to-end QoS, may be based on SLAs with other providers and may be using some NSIS signaling.
 
For the packet path from B -> A, A does not know apriori as to how the path looks like. So, the QoS establishment for this path needs to be initiated from B's side. Now, B is not paying for QoS in its own access network N_B. Since, A has agreed to pay, A needs to provide some credentials to B which would be acceptable to N_B. There are two problems encountered here: i) Though A has agreed to pay, A may not be willing to provide credentials to end host B for security reasons, ii) If A and N_B are in different jurisdiction, whatever credentials A has to provide may not satisfy N_B. Note that N_B cannot bill A directly.
 
The following things need to happen to make this call through. 
 
(i) SIP has to convey "intent" of A to pay for the call to B. A may also expect in return the B's cost of access at N_B. (This part has to be addressed by SIP and SDPng).
 
(ii)  NSIS signaling needs to interwork with AAA so that it can reserve and bill for QoS resources in N_B. This is the requirement that needs to be included in NSIS requirements document.
 
BR,
Hemant

---

From: "Hannes Tschofenig" <[email-masked]>
Date: Wed, 13 Mar 2002 10:56:21 +0100

hi hemant!

> I would like to place the following requirement on table for discussion in
WG. I have also provided a scenario below that

> motivates such explicit requirement. I would like to know if WG deems this
as an important issue.

> "QoS signaling protocol MUST interwork with AAA for QoS authorization and
accounting purposes".

i like this requirement. it think that it is a good idea to have this
requirement.

but: i think it is already covered with:

5.8.2 The QoS protocol must provide means to authorize resource requests

5.10.5 The QoS protocol should provide hooks for AAA protocols

appart from the requirements for an interaction with AAA there are still
open issues regarding billing/payment/charging

as indicated below. there have been a number of papers describing different
solutions

but i do not know a satisfiable one. maybe we can discuss some of the issues
at the ietf conference

next week.

to your scenario below:

just to make sure: the main problem seems to be that user B has to give
"something" to network N_B telling that user A is paying for

the reservation.

if A is not willing to provide credentials then there is obvioulsy a problem
but

a could provide credentials without concerns about security. it only depends
how these "credentials" look like.

from my point of view this information should be exchanged before the actual
qos reservation takes place since it

is an application issue. hence the information should already be available
at the qos-reservation start-up.

> ii) If A and N_B are in different jurisdiction, whatever credentials A has
to provide may not satisfy N_B.

> Note that N_B cannot bill A directly.

there has to be some agreement between providers otherwise this exchange
will not work.

> (i) SIP has to convey "intent" of A to pay for the call to B. A may also
expect in return the B's cost of access at N_B.

> (This part has to be addressed by SIP and SDPng).

i agree with you.

> (ii) NSIS signaling needs to interwork with AAA so that it can reserve and
bill for QoS resources in N_B.

> This is the requirement that needs to be included in NSIS requirements
document.

this is true.

first, the qos signaling messages must be authenticated, integrity and
replay protected.

second, the qos protocol should be able to transport information exchanged
with protocols executed before the

qos protocol is triggered.

ciao

hannes

  -----Original Message-----
  From: [email-masked] [mailto:[email-masked]]On Behalf Of
[email-masked]
  Sent: Tuesday, March 12, 2002 4:55 PM
  To: [email-masked]
  Subject: [NSIS] An NSIS requirement with backing scenario

  Hi:

  I would like to place the following requirement on table for discussion in
WG. I have also provided a scenario below that motivates such explicit
requirement. I would like to know if WG deems this as an important issue.

  "QoS signaling protocol MUST interwork with AAA for QoS authorization and
accounting purposes".

  Scenario:
  -----------

  A and B are connected to the Internet on the two sides of the globe. A
places call to B, and (say during SIP transactions) intimates to B that A
will pay for the call. Paying for the call also means paying for QoS of the
corresponding packet transport. B accepts A's proposal. The call happens to
be of bidirectional traffic type.

  A sends signal to its access network N_A asking it to give certain QoS to
packet stream from A -> B. A is a subscribed customer of N_A, so there are
no apparent difficulties for N_A in checking A's credentials and in billing
A. Also, network N_A may then take appropriate means to guarantee end-to-end
QoS, may be based on SLAs with other providers and may be using some NSIS
signaling.

  For the packet path from B -> A, A does not know apriori as to how the
path looks like. So, the QoS establishment for this path needs to be
initiated from B's side. Now, B is not paying for QoS in its own access
network N_B. Since, A has agreed to pay, A needs to provide some credentials
to B which would be acceptable to N_B. There are two problems encountered
here: i) Though A has agreed to pay, A may not be willing to provide
credentials to end host B for security reasons, ii) If A and N_B are in
different jurisdiction, whatever credentials A has to provide may not
satisfy N_B. Note that N_B cannot bill A directly.

  (i) SIP has to convey "intent" of A to pay for the call to B. A may also
expect in return the B's cost of access at N_B. (This part has to be
addressed by SIP and SDPng).

  (ii)  NSIS signaling needs to interwork with AAA so that it can reserve
and bill for QoS resources in N_B. This is the requirement that needs to be
included in NSIS requirements document.

  BR,
  Hemant