Subject: RE: [Megaco] Handoff triggered from MGC to NewMgc

From: "Rambabu Gajula" <[email-masked]>
Date: Mon, 7 May 2007 09:26:51 +0530

Dear Experts,

I would really appreciate if some one answers for below queries.

Thanks with regards,

Rambabu Gajula

________________________________

From: Rambabu Gajula [mailto:[email-masked]] 
Sent: Friday, May 04, 2007 10:46 AM
To: [email-masked]
Subject: [Megaco] Handoff triggered from MGC to NewMgc

Hi,

During MGC initiated Handoff request to MGW, the MGW should aware off
the new MGC(ServiceChangeMgcID) ?

MGW can allow to start control association with new MGC which is not
aware of that MGCId at MGW level?

1) Is this not cause any security/un authorized more attacks on MGCs?

2) Is there any mechanism on run time to exchange which
encoding/decoding scheme(ASN/ABNF)should be used in new control
associations?

Thanks a lot for your time and help.

Thanks with Regards,

Rambabu Gajula

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https://www1.ietf.org/mailman/listinfo/megaco

---

From: [email-masked]
Date: Thu, 10 May 2007 08:45:22 +0200

The "ServiceChangeMgcID" topic was discussed at last Rapporteurs' meeting,
see new § 8 H.248 Control Association: Summary of scenarios with usage of
ServiceChangeMgcID parameter

in

Updated draft new ITU-T Supplement H.Sup7 (ex H248CtrlAssoc)  "Gateway
Control Protocol: Establishment Procedures for the H.248 MGC-MG Control
Association" (Ed. 0.10)
http://ftp3.itu.int/av-arch/avc-site/2005-2008/0703_She/TD-41.zip

Your specific questions were not discussed.

>1) Is this not cause any security/un authorized more attacks on MGCs?

It depends. You could do before e.g. a (limited) "MGC verification",
dependent on provisioned information.
See § 5.5.2.1/H.Sup7.
This clause is prepared for such function. Currently there is just some
initial text.

>2) Is there any mechanism on run time to exchange which encoding/decoding
scheme(ASN/ABNF)should be used in new control associations?

You firstly have to clarify your understanding concerning "run time" versus
"Control Association"?
An "H.248 Message Codec change" is only possible with a "profile change" in
my understanding.
Such a capability change may lead to a release & re-establishment of the
CA, at least to a renewal of the CA.
See also H.Sup7:
§ 9 H.248 Control Association: Impact of Protocol Version changes and/or
Profile changes on established Control AssociationsAnyway, there's impact
on the CA.

Perhaps you could provide further proposals for § 9?

                      "Rambabu Gajula"                                                                                               
                      <rambabu.gajula@         To:      "Rambabu Gajula" <[email-masked]>, <[email-masked]>                
                      ccpu.com>                cc:                                                                                   
                                               Subject: RE: [Megaco] Handoff  triggered from MGC to NewMgc                           
                      07.05.2007 05:56                                                                                               

Dear Experts,

Thanks with regards,
Rambabu Gajula

Hi,

During MGC initiated Handoff request to MGW, the MGW should aware off the
new MGC(ServiceChangeMgcID) ?

MGW can allow to start control association with new MGC which is not aware
of that MGCId at MGW level?

1) Is this not cause any security/un authorized more attacks on MGCs?
2) Is there any mechanism on run time to exchange which encoding/decoding
scheme(ASN/ABNF)should be used in new control associations?

(Embedded image moved to file: pic16838.pcx)Thanks with Regards,
Rambabu Gajula