Re: [ippm] WGLC for STAMP Extensions

["Rakesh Gandhi (rgandhi)" <[e-mail]>]

Hi Greg,
The current (OLD) text in the document looks good to me.
P.S. The goal for STAMP (with Simple) is to simplify such things when compared to TWAMP (RFC 5357).

Thanks,
Rakesh


From: ippm <[e-mail]> on behalf of Greg Mirsky <[e-mail]>
Date: Thursday, June 11, 2020 at 10:21 AM
To: Rakesh Gandhi <[e-mail]>
Cc: "MORTON, ALFRED C (AL)" <[e-mail]>, Ian Swett <ianswett=[e-mail]>, "IETF IPPM WG ([e-mail])" <[e-mail]>
Subject: Re: [ippm] WGLC for STAMP Extensions

Hi Rakesh,
I agree with your scenario. Do you feel that the document, including the updated text, precludes it? Would you suggest text clarifications?

Regards,
Greg

On Thu, Jun 11, 2020 at 7:13 AM Rakesh Gandhi <[e-mail]<mailto:[e-mail]>> wrote:
Thanks Greg.
SSID can be internally generated by the sender node. Expecting sender node to communicate this to the controller and then to the reflector node for *each* session may be overkill.

The destination UDP port to use on the reflector node is already provisioned value and not any arbitrary port can be used anyways. So that should help with such issues.

My 2c.

Thanks,
Rakesh



On Wed, Jun 10, 2020 at 9:32 PM Greg Mirsky <[e-mail]<mailto:[e-mail]>> wrote:
Hi Rakesh,
as Al clarified, and I agree with this scenario, a Session-Reflector must be provisioned with a session identifier (some elements, I think, might be specified as a wild card) before the session is commenced. All test packets that do not match the provisioned identifier must be discarded without processing. I've tried to capture that in the latest update sent earlier.
What do you think of this scenario?

Regards,
Greg

On Wed, Jun 10, 2020 at 4:36 PM Rakesh Gandhi <[e-mail]<mailto:[e-mail]>> wrote:
Hi Greg, Al,
I am not sure if I follow the scenario.
Between nodes A and B, there can be more than one STAMP sessions, e.g. {Node-A, Node-B, Src-Port-1, Dst-Port-1, SSID1} and {Node-A, Node-B, Src-Port-1, Dst-Port-1, SSID2}. I assume this is allowed? If yes, how do we know when there is now a third session between them with SSID3 (with same 4 tuple), it is a change (from SSID1 or SSID2?) or a new third session?
Thanks,
Rakesh




On Wed, Jun 10, 2020 at 7:21 PM Greg Mirsky <[e-mail]<mailto:[e-mail]>> wrote:
Hi Al,
many thanks for your quick response, much appreciated. We'll need some more time to discuss your suggestion related to the Access Report TLV. I've front-copied the other open issue and added my notes under the tag GIM2>> below.

   An implementation of STAMP Session-Reflector that supports this
   specification SHOULD identify a STAMP Session using the SSID in
   combination with elements of the usual 4-tuple
[acm] <insert> for the session. If the Session-Reflector finds that
the SSID and 4-tuple combination changes during a test session, then
the Session-Reflector MUST discard the non-matching packet(s) and take
no further action on them.
   .  A conforming...
GIM>> We've discussed the scenario and couldn't define how a Session-Reflector can distinguish between a new STAMP test session and the event of a change in identifiers, i.e., SSID and 4-tuple of the ongoing test session. Could you kindly help us here?

[acm] Thanks, I’m surprised that a new test session (with new SSID) can begin without any Session-Reflector agreement or communication from the Session-Reflector’s management interface. Since the Sending address and port could be spoofed, Session-Reflectors could receive lots of unexpected traffic, if you know what I mean.....
GIM2>> Thank you for the clarification. I was not thinking out of a box. Please review the proposed new text below. I hope it captures the scenario you've pointed out.
OLD TEXT:
   An implementation of STAMP Session-Reflector that supports this
   specification SHOULD identify a STAMP Session using the SSID in
   combination with elements of the usual 4-tuple for the session.  A
   conforming implementation of STAMP Session-Reflector MUST copy the
   SSID value from the received test packet and put it into the
   reflected packet, as displayed in Figure 2.
NEW TEXT:
   An implementation of STAMP Session-Reflector that supports this
   specification SHOULD identify a STAMP Session using the SSID in
   combination with elements of the usual 4-tuple for the session.
   Before a test session commenced, a Session-Reflector MUST be
   provisioned with all the elements that identify the STAMP Session.  A
   STAMP Session-Reflector MUST discard the non-matching STAMP test
   packet(s).  The means of provisioning the STAMP Session
   identification is outside the scope of this specification.  A
   conforming implementation of STAMP Session-Reflector MUST copy the
   SSID value from the received test packet and put it into the
   reflected packet, as displayed in Figure 2.

Would the new text address your concern?

Regards,
Greg


On Wed, Jun 10, 2020 at 8:01 AM MORTON, ALFRED C (AL) <[e-mail]<mailto:[e-mail]>> wrote:
Hi Greg, Thanks for all replies.
Let’s concentrate on those needing some additional thought...
Al


   An implementation of STAMP Session-Reflector that supports this
   specification SHOULD identify a STAMP Session using the SSID in
   combination with elements of the usual 4-tuple
[acm] <insert> for the session. If the Session-Reflector finds that
the SSID and 4-tuple combination changes during a test session, then
the Session-Reflector MUST discard the non-matching packet(s) and take
no further action on them.
   .  A conforming...
GIM>> We've discussed the scenario and couldn't define how a Session-Reflector can distinguish between a new STAMP test session and the event of a change in identifiers, i.e., SSID and 4-tuple of the ongoing test session. Could you kindly help us here?

[acm] Thanks, I’m surprised that a new test session (with new SSID) can begin without any Session-Reflector agreement or communication from the Session-Reflector’s management interface. Since the Sending address and port could be spoofed, Session-Reflectors could receive lots of unexpected traffic, if you know what I mean.....


...
 …                 | 2     |   Non-3GPP  | This document |
                  +-------+-------------+---------------+
[acm] these seem overly broad, and unlikely to be extended because they *cover everything*!!
GIM>> Here we've turned to our 3GPP expert... The current (Rel-16) specification of ATSSS defines only two access types - 3GPP and Non-3GPP. Creating a sub-registry and leaving a space for new types might help to accommodate potential changes in 5G specification and the development of new specifications, e.g., 6G, in the future.
[acm]
Yes, but your examples of 5G and 6G would fall under the general category of “3GPP” (which I accidentally delated above).
Maybe some additional detail would help, like “3GPP-LTE”, “3GPP-5G”, and make “Non-3GPP” the first entry so that expansion with new technologies starts at 2, 3, …
                            Table 8: Access IDs

...

              +-------+---------------------+---------------+
              | Value |     Description     | Reference     |
              +-------+---------------------+---------------+
              | 1     |  Network available  | This document |
              | 2     | Network unavailable | This document |
              +-------+---------------------+---------------+
[acm] these seem overly broad, and imply knowledge where the STAMP end-point has limited insights!!
GIM>>  These are defined in ATSSS specification of Performance Measurement Function. The value for the Return Code field is passed to STAMP system and it only transports it. Would a new text clarify the role of a STAMP system:
OLD TEXT:
   o  Return Code - one octet long field that identifies the report
      signal, e.g., available, unavailable.  The value is one of those
      listed in Section 5.5.
NEW TEXT:
   o  Return Code - one octet long field that identifies the report
      signal, e.g., available, unavailable.  The value is passed,
      supplied to the STAMP end-point through some mechanism that is
      outside the scope of this document.  The value is one of those
      listed in Section 5.5.
[acm]
OK
                          Table 10: Return Codes

...

6.  Security Considerations

   Use of HMAC in authenticated mode may be used to simultaneously
   verify both the data integrity and the authentication of the STAMP
   test packets.
[acm] That's it? At least add reference to STAMP 8762 Security Section?
GIM>> Thank you for your suggestion. The new text is below:
NEW TEXT:
   This document defines extensions to STAMP [RFC8762] and inherits all
   the security considerations applicable to the base protocol.
   Additionally, the HMAC TLV is defined in this document to protect the
   integrity of optional STAMP extensions.  The use of HMAC TLV is
   discussed in detail in Section 4.8.

[acm] OK
[acm] I suspect there will be some challenges for "Location" in future


From: ippm [mailto:[e-mail]<mailto:[e-mail]>] On Behalf Of Ian Swett
Sent: Friday, May 22, 2020 5:26 PM
To: IETF IPPM WG ([e-mail]<mailto:[e-mail]>) <[e-mail]<mailto:[e-mail]>>
Subject: [ippm] WGLC for STAMP Extensions

Hi IPPM,

At our virtual interim meeting, we decided draft-ietf-ippm-stamp-option-tlv was ready for last call. This email starts a two-week WGLC for this draft.

The latest version can be found here: https://tools.ietf.org/html/draft-ietf-ippm-stamp-option-tlv-04<https://urldefense.proofpoint.com/v2/url?u=https-3A__tools.ietf.org_html_draft-2Dietf-2Dippm-2Dstamp-2Doption-2Dtlv-2D04&d=DwMFaQ&c=LFYZ-o9_HUMeMTSQicvjIg&r=OfsSu8kTIltVyD1oL72cBw&m=-FQ_7VkardtUOemNdXjWGCdxDzw_8jcaV16Ots-GfRo&s=zadhVvE6IwVbJd0BcDUJdpX4xXqA4i60susVdbT5Pvg&e=>

This last call will end on Monday, June 8th. Please reply to [e-mail]<mailto:[e-mail]> with your reviews and comments.

Thanks,
Ian & Tommy
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