Subject: Re: FW: Application for port-number

From: Tom-PT Taylor <[email-masked]>
Date: Fri, 14 Jan 2000 10:44:42 -0500

On your first point, the only purpose of these ports is to give the MG
somewhere to go to initiate the association.  If it's TCP, the MG port is
fixed at that point.  If it's UDP, the MG can signal which port it wants to
receive at.

I thought about your second point, but figured the outcome would be the
same, regardless: if the MGC doesn't understand a particular encoding, it
will have no choice but to ignore the association attempt, since it won't
even be able to recognize the protocol.  Perhaps that's a hole we should fix
so the MG can at least be told that the MGC doesn't understand it.

> -----Original Message-----
> From: Christian Huitema [SMTP:[email-masked]]
> Sent: Friday, January 14, 2000 10:22 AM
> To:   Taylor, Tom-PT [CAR:B904:EXCH]; [email-masked]
> Subject:      Re: FW: Application for port-number
>
> At 01:35 PM 1/12/00 -0600, Tom-PT Taylor wrote:
> >I've requested a single port number pair (TCP/UDP) for Megaco/H.248.  See
> >below.
>
> In fact, it would make sense to require separate port numbers for the MG
> and for the MGC, to facilitate the writing of ACL in firewalls or similar
> devices. Also, it might make sense to use separate port numbers for the
> text and ASN.1 encodings -- that would limit confusion.
> -- Christian Huitema

---

From: Abdallah Rayhan <[email-masked]>
Date: Fri, 14 Jan 2000 11:51:19 -0500

Either a different port or a BinaryToken in the ASN.1 to differentiate
binary and text. Or the other way around in the ABNF, e.g., you look
for a particular token  at the beginning the message. If present then
binary encoding is assumed, otherwise text encoding.

Abdallah Rayhan

"Taylor, Tom-PT (P.T.) [EXCHANGE:CAR:B904]" wrote:

> somewhere to go to initiate the association.  If it's TCP, the MG port
> is fixed at that point.  If it's UDP, the MG can signal which port it
> wants to receive at.
>
> I thought about your second point, but figured the outcome would be
> the same, regardless: if the MGC doesn't understand a particular
> encoding, it will have no choice but to ignore the association
> attempt, since it won't even be able to recognize the protocol.
> Perhaps that's a hole we should fix so the MG can at least be told
> that the MGC doesn't understand it.
>