Re: How can I make the server to call back to client without being blocked by firewall.

From: jeff Lee (jeff-lee@attbi.com)
Date: 10/04/02 

From: "jeff Lee" <jeff-lee@attbi.com>
Date: Fri, 04 Oct 2002 13:12:20 GMT

Thanks Alun,

But a little bit confusing about your's and Emil's comments.

Her post says the UDP will always be blocked by firewall.
I am assuming this is the case when Administrator keep the default
fire settings on the UDP port the traffic will come in.

Your post says "the firewall allow that". So I am assuming this is the case
when firewall is configured to allow the traffic in on the UDP port?
Am I correct? Thanks for clear this.

Regards,
Jeff

"Alun Jones" <alun@texis.com> wrote in message
news:OOCm9.67$0J.73033845@newssvr12.news.prodigy.com...
> In article <cJum9.5149$Pz.9443@rwcrnsc51.ops.asp.att.net>, "jeff Lee"
> <jeff-lee@attbi.com> wrote:
> >Another question though. Since UDP can also be in connection mode even
> >though it's not exactly
> >the same with TCP, can client make a UDP connection and keep it open
> >so that server can send some data back without being blocked by firewall?
>
> NATs and other firewalls that allow outgoing UDP packets are often aware
that
> some protocols require a channel in the other direction, and will allow
that,
> as if there were really a connection - unless, of course, the firewall
> administrator has chosen to ban that.
>
> Alun.
> ~~~~
>
> [Please don't email posters, if a Usenet response is appropriate.]
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