From: "Glenn Meadows" 

Interesting.  Wonder how this differs from the IP based internal 3Com phone
system we use, that runs over our internal lan, and then bops out over a
T-1?  Yea, I know it's not VOIP when it leaves here, but wonder what it's
called internally?

We were connecting to our Atlanta and LA offices over our Frame relay with
this system (had one in each office, with dedicated IP addresses/channels
on the Frame to handle the voice stuff).  Never got it fully working right,
in that we were eventually going to be able to dial a number in LA or
Atlanta, and the call would route down the frame, and then grab an outside
line in the other offices.  Guess they never got the dial plans working
right, or something.

--
Glenn M.


"Rich Gauszka"  wrote in message
news:41f68c10$1{at}w3.nls.net...
> Dunno. It does look like VOIP needs quite a few ports open
>
> http://www.bcr.com/bcrmag/2002/07/p10.php
>
> But if you want to let VOIP traffic move from a public IP network onto
your
> premises, you have to leave lots of ports open, explained Gary Audin,
> president of consultancy Delphi, Inc. For each voice conversation, two TCP
> or UDP ports have to be opened to allow H.323 or Session Initiation
Protocol
> (SIP) signaling-one port for each direction. Then, for the voice traffic
> itself, two UDP ports must be opened and, optionally, two more UDP ports
may
> be opened for Real-Time Control Protocol (RTCP), which monitors
performance.
>
> The VOIP ports run in sequences starting with Port 1024, which is a talk
> port, then 1025 to monitor 1024, then Port 1026 to listen, 1027 to monitor
> 1026, and so on, Audin explained.
>
> Note that 2-4 UDP ports must be open for the duration of each call. If you
> need to support more than one simultaneous phone call, you'll have to open
> up a pool of many more ports. "You can create a blocking environment at
your
> firewall if you run out of ports that are in your pool," Audin said.
>
> "Glenn Meadows"  wrote in message
> news:41f682eb$1{at}w3.nls.net...
> > Won't a consumer Firewall/router block those ports accessing anyway?
(Not
> > sure what David's seeing/having a problem with, but I would think his
> > entrance router should keep all the VOIP traffic out of his internal
> > network.)
> >
> >
> > --
> > Glenn M.
> >
> >
> > "Rich Gauszka"  wrote in message
> > news:41f670f4$1{at}w3.nls.net...
> >> You can try blocking udp/tcp port 5060
> >>
> >> http://techdirt.com/articles/20041028/0212235.shtml
> >>
> >> BT has put in place a fairly simplistic, but obvious, block on most
third
> >> party VoIP providers . All they're doing is blocking port 5060, which
is
> >> often used by SIP servers.
> >>
> >> "David B"  wrote in message
> >> news:41f65fa9$1{at}w3.nls.net...
> >> > I'm not sure this would be an option since this is for a personal
net,
> > not
> >> > a corporate one.
> >> >
> >> > I was hoping to block some ports if needed.
> >> > "Geo"  wrote in message
news:41f628f6$1{at}w3.nls.net...
> >> >> www.fortinet.com
> >> >>
> >> >> not cheap but it can block skyPE and I believe it
can do layer 7
> >> >> filtering.
> >> >>
> >> >> Geo.
> >> >>
> >> >> "David B" 
wrote in message
> >> >> news:41f52cde$1{at}w3.nls.net...
> >> >>> Is there a way to block VOIP? Is it a standard
port? I have someone
> >> >>> using
> >> >>> something called GloPhone and I would like to
block it at my
router.
> >> >>>
> >> >>>
> >> >>
> >> >>
> >> >
> >> >
> >>
> >>
> >
> >
>
>

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