Subject: RE: [Megaco] RE: From whence they came?

From: "Jaiswal, Vivek" <[email-masked]>
Date: Mon, 13 Aug 2001 15:25:00 -0700

Hi 
This is with respect to the final decision on the usage of "MgcIdToTry" in
case of service change reply & handoff procedures.
I would like to know whether this decision implies that "mgcIdToTry" in SVC
reply or during handoff procedures can "never" be a domain name??? 

And if it can be a domain name, this would imply that, initially the new
peer is identified based on domain name, then the same peer is identified
based on IP address (Once that is obtained from DNS), and only after the
first message is received from the new MGC, will the MG "really" come to
know who its MGC is!!!

Is this correct, or I am missing something?

Vivek Jaiswal 

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Hi Tom, 

  just to clarify what you are saying, in your scenario the control
association establishment goes like this:

1. MG contacts MGC1 which gives it an "MgcIdToTry = 1.2.3.4" (IP address) in
ServiceChange reply.

2. MG contacts IP address 1.2.3.4 on port 2944 and gets a ServiceChange
reply with mId = "5.6.7.8" (or "Controller1").

3. MG now knows that mId = 5.6.7.8  corresponds to an MGC with IP address
1.2.3.4.

If MG was provisioned with more than two (one?) eligible MGCs, it would not
know until step 3 which MGC it actually is talking to. MgcIdToTry is ALWAYS
a valid transport address (never something like "Controller1" even though it
may fit the mId syntax and in fact may be the mId of the new MGC). 

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-----Original Message-----
From: Tom-PT Taylor [mailto:[email-masked]]
Sent: Tuesday, July 24, 2001 6:04 PM
To: 'Kaul, Bharat'; Tulpule, Naren; [email-masked]'
Subject: [Megaco] RE: From whence they came?

Yes, I agree.

Tom Taylor
[email-masked]
Ph. +1 613 736 0961 (ESN 396 1490)

-----Original Message-----
From: Kaul, Bharat [mailto:[email-masked]]
Sent: Tuesday, July 24, 2001 6:14 PM
To: Tulpule, Naren; Taylor, Tom-PT [NORSE:B881:EXCH]; [email-masked]'
Subject: RE: From whence they came?

Tom/List,
 
  I would like to find out if we are on the same page as described below by
Naren on this issue. This thread suddenly stopped without a conclusion and I
would to find out if we concur with suggested behaviour.
 
- Thanks
  Bharat

-----Original Message-----
From: Tulpule, Naren [mailto:[email-masked]]
Sent: Wednesday, July 18, 2001 12:36 PM
To: 'Tom-PT Taylor'; [email-masked]
Subject: RE: From whence they came?

-----Original Message-----
From: Tom-PT Taylor [mailto:[email-masked]]

Hi.  I'll be stubborn here and say that the MG has to know that the messages
are coming from the intended MGC by other means.  One of those means might
be that the MGC response to the initial ServiceChange came back to the port
from which the MG dispatched the ServiceChange request.  Another possibility
(requiring prior implementation agreement) is that the MG is provisioned
with the MId by which it will recognize each MGC which is eligible to
control it.

[Naren] Hi Tom,

  just to clarify what you are saying, in your scenario the control
association establishment goes like this:

1. MG contacts MGC1 which gives it an "MgcIdToTry = 1.2.3.4" (IP address) in
ServiceChange reply.

2. MG contacts IP address 1.2.3.4 on port 2944 and gets a ServiceChange
reply with mId = "5.6.7.8" (or "Controller1").

3. MG now knows that mId = 5.6.7.8  corresponds to an MGC with IP address
1.2.3.4.

If MG was provisioned with more than two (one?) eligible MGCs, it would not
know until step 3 which MGC it actually is talking to. MgcIdToTry is ALWAYS
a valid transport address (never something like "Controller1" even though it
may fit the mId syntax and in fact may be the mId of the new MGC). 

 -----Original Message----- 
From: Tulpule, Naren [ mailto:[email-masked] <mailto:[email-masked]>
] 
Sent: Wednesday, July 18, 2001 2:03 PM 
To: Taylor, Tom-PT [NORSE:B881:EXCH]; [email-masked]'; [email-masked]

Subject: RE: From whence they came? 

-----Original Message----- 
From: Tom-PT Taylor [ mailto:[email-masked]
<mailto:[email-masked]> ] 

One key point to note is that MGCIdToTry and ServiceChangeAddress are
destination addresses to which the receiver of the ServiceChange is to pass
requests.  Requests from the other end may come from an address different
from the ServiceChangeAddress or the initial contact address. 

[Naren] True enough. 
Now, in the requests from  the new MGC to our MG; will that MGC use an mId
which is exactly the "MgcIdToTry" given to our MG by the old MGC? 

In that case, "MgcIdToTry" has to be both (a) a valid "resolvable" transport
identifier such as host.domain.com:12345 and (b) a logical opaque handle
which never changes during the control association between our MG and the
new MGC. So MgcIdToTry cannot be something like "Controller1". 

If not, how does the MG know a request came from the new MGC? 
All this confusion over mId arose because we have overloaded its use as a
logical handle AND (in some situations) a transport ID (such as IP address).
In v2, we should cleanly seperate the two - e.g. "EntityName" and
"ControlAssociationAddress".

---

From: "Tom-PT Taylor" <[email-masked]>
Date: Tue, 21 Aug 2001 14:23:41 -0400

The real identity of the MGC doesn't really matter so long as security
requirements are met.  From a protocol point of view all that matters is
that the MG know where to send its messages.

-----Original Message-----
From: Jaiswal, Vivek [mailto:[email-masked]]
Sent: Monday, August 13, 2001 6:25 PM
To: Taylor, Tom-PT [NORSE:B881:EXCH]; Kaul, Bharat; Tulpule, Naren;
[email-masked]'
Subject: RE: [Megaco] RE: From whence they came?

Hi 

Vivek Jaiswal 

Hi Tom, 

-----Original Message-----
From: Tom-PT Taylor [mailto:[email-masked]]
Sent: Tuesday, July 24, 2001 6:04 PM
To: 'Kaul, Bharat'; Tulpule, Naren; [email-masked]'
Subject: [Megaco] RE: From whence they came?

Yes, I agree.

Tom Taylor

-----Original Message-----
From: Kaul, Bharat [mailto:[email-masked]]
Sent: Tuesday, July 24, 2001 6:14 PM
To: Tulpule, Naren; Taylor, Tom-PT [NORSE:B881:EXCH]; [email-masked]'
Subject: RE: From whence they came?

Tom/List,

- Thanks
  Bharat

-----Original Message-----
From: Tulpule, Naren [mailto:[email-masked]]
Sent: Wednesday, July 18, 2001 12:36 PM
To: 'Tom-PT Taylor'; [email-masked]
Subject: RE: From whence they came?

-----Original Message-----

[Naren] Hi Tom,

-----Original Message----- 

[Naren] True enough.

---

From: "Kaul, Bharat" <[email-masked]>
Date: Tue, 21 Aug 2001 12:26:35 -0700

Tom,
 
I agree with the statement you made as long as "MG knows where to send its
messages". I think what we need to make clear here is that:
 
MgcIdToTry is never a MID (i.e. it is not a logical identifier). It is
always a transport address (domain name or IP Address). This is different
from MID identifies the source of the message.
 
If above statement is TRUE, then I think we should be ok from protocol
perspective otherwise we have a problem.
 
- Bharat

-----Original Message-----
From: Jaiswal, Vivek [mailto:[email-masked]]
Sent: Monday, August 13, 2001 6:25 PM
To: Taylor, Tom-PT [NORSE:B881:EXCH]; Kaul, Bharat; Tulpule, Naren;
[email-masked]'

Hi 

Vivek Jaiswal 

Hi Tom, 

-----Original Message-----
From: Tom-PT Taylor [mailto:[email-masked]]
Sent: Tuesday, July 24, 2001 6:04 PM
To: 'Kaul, Bharat'; Tulpule, Naren; [email-masked]'
Subject: [Megaco] RE: From whence they came?

Yes, I agree.

---

From: "Tom-PT Taylor" <[email-masked]>
Date: Thu, 23 Aug 2001 11:18:04 -0400

Agreed.

-----Original Message-----
From: Kaul, Bharat [mailto:[email-masked]]
Sent: Tuesday, August 21, 2001 3:27 PM
To: Taylor, Tom-PT [NORSE:B881:EXCH]; Jaiswal, Vivek; Kaul, Bharat; Tulpule,
Naren; [email-masked]'

Tom,

 
 
- Bharat

-----Original Message-----
From: Jaiswal, Vivek [mailto:[email-masked]]
Sent: Monday, August 13, 2001 6:25 PM
To: Taylor, Tom-PT [NORSE:B881:EXCH]; Kaul, Bharat; Tulpule, Naren;
[email-masked]'

Hi 

Vivek Jaiswal 

Hi Tom, 

-----Original Message-----
From: Tom-PT Taylor [mailto:[email-masked]]
Sent: Tuesday, July 24, 2001 6:04 PM
To: 'Kaul, Bharat'; Tulpule, Naren; [email-masked]'
Subject: [Megaco] RE: From whence they came?

Yes, I agree.

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