Use WCF to make firewall-tolerant 'collaboration' environment?

I'm looking at creating a kind of collaboration /
teaching environment using WCF. I want to be able
to have the teacher do events that get pushed to
all the student machines (like pointing at some
part of a diagram).

To avoid problems with the client's firewalls and
NATs it seems like the best thing would be a
single "permanent" TCP connection on port 80 from
the clients (students) to the server (teacher).

Is it possible to set this up with WCF so that the
one physical TCP connection over port 80 can transmit
multiple "streams" of data simultaneously? For
example, it would be nice to have a lower priority file
transfer flowing in either direction, while at the same
time having little event packets at a high priority
flowing in both directions too.

How much of this can be done with WCF?

Thanks,
Alex

No, you need UDP for multicast/broadcast. That not have default support in
WCF but you have SDK example of such.
Arkady

<AlexC> wrote in message news:egtjn2hsvjemtbicmsh12tcj29mrt79pe5@4ax.com...
> I'm looking at creating a kind of collaboration /
> teaching environment using WCF. I want to be able
> to have the teacher do events that get pushed to
> all the student machines (like pointing at some
> part of a diagram).
>
> To avoid problems with the client's firewalls and
> NATs it seems like the best thing would be a
> single "permanent" TCP connection on port 80 from
> the clients (students) to the server (teacher).
>
> Is it possible to set this up with WCF so that the
> one physical TCP connection over port 80 can transmit
> multiple "streams" of data simultaneously? For
> example, it would be nice to have a lower priority file
> transfer flowing in either direction, while at the same
> time having little event packets at a high priority
> flowing in both directions too.
>
> How much of this can be done with WCF?
>
> Thanks,
> Alex

Forgot to put the link :
http://msdn2.microsoft.com/en-us/library/ms751494.aspx
Arkady

"Arkady Frenkel" <arkadyf@hotmailxdotx.com> wrote in message
news:ua%23Ta73GHHA.1276@TK2MSFTNGP04.phx.gbl...
> No, you need UDP for multicast/broadcast. That not have default support in
> WCF but you have SDK example of such.
> Arkady
>
> <AlexC> wrote in message
> news:egtjn2hsvjemtbicmsh12tcj29mrt79pe5@4ax.com...
>> I'm looking at creating a kind of collaboration /
>> teaching environment using WCF. I want to be able
>> to have the teacher do events that get pushed to
>> all the student machines (like pointing at some
>> part of a diagram).
>>
>> To avoid problems with the client's firewalls and
>> NATs it seems like the best thing would be a
>> single "permanent" TCP connection on port 80 from
>> the clients (students) to the server (teacher).
>>
>> Is it possible to set this up with WCF so that the
>> one physical TCP connection over port 80 can transmit
>> multiple "streams" of data simultaneously? For
>> example, it would be nice to have a lower priority file
>> transfer flowing in either direction, while at the same
>> time having little event packets at a high priority
>> flowing in both directions too.
>>
>> How much of this can be done with WCF?
>>
>> Thanks,
>> Alex
>
>

Hi Arkady,

Thanks for your comments and the pointer to the UDP
transport sample.

But if I have to create a custom WCF transport, does that
mean the design I described would be "fighting" the normal
WCF way of doing things? In other words, is there some
other design (maybe several simultaneous TCP connections
between each client and server, one for file transfers, one
for commands, ...) that is a more normal way to accomplish
the same thing in the WCF world?

Thanks,
Alex

On Sat, 9 Dec 2006 12:45:11 +0200, "Arkady Frenkel"
<arkadyf@hotmailxdotx.com> wrote:

>No, you need UDP for multicast/broadcast. That not have default support in
>WCF but you have SDK example of such.
>Arkady
>
><AlexC> wrote in message news:egtjn2hsvjemtbicmsh12tcj29mrt79pe5@4ax.com...
>> I'm looking at creating a kind of collaboration /
>> teaching environment using WCF. I want to be able
>> to have the teacher do events that get pushed to
>> all the student machines (like pointing at some
>> part of a diagram).
>>
>> To avoid problems with the client's firewalls and
>> NATs it seems like the best thing would be a
>> single "permanent" TCP connection on port 80 from
>> the clients (students) to the server (teacher).
>>
>> Is it possible to set this up with WCF so that the
>> one physical TCP connection over port 80 can transmit
>> multiple "streams" of data simultaneously? For
>> example, it would be nice to have a lower priority file
>> transfer flowing in either direction, while at the same
>> time having little event packets at a high priority
>> flowing in both directions too.
>>
>> How much of this can be done with WCF?
>>
>> Thanks,
>> Alex
>

What do you mean "fighting", that just a way standard WCF not use , because
UDP is not reliable protocol ( packets could be dropped on the way and
sender know nothing about it ). So you need to add some reliability checking
to that ( BTW additionally WCF provide that for TCP too ). Sure you can send
that in TCP to all clients attached to service.
Arkady

<AlexC> wrote in message news:15mln254v3gtqc14rpla201duv51usnvd1@4ax.com...
> Hi Arkady,
>
> Thanks for your comments and the pointer to the UDP
> transport sample.
>
> But if I have to create a custom WCF transport, does that
> mean the design I described would be "fighting" the normal
> WCF way of doing things? In other words, is there some
> other design (maybe several simultaneous TCP connections
> between each client and server, one for file transfers, one
> for commands, ...) that is a more normal way to accomplish
> the same thing in the WCF world?
>
> Thanks,
> Alex
>
> On Sat, 9 Dec 2006 12:45:11 +0200, "Arkady Frenkel"
> <arkadyf@hotmailxdotx.com> wrote:
>
>>No, you need UDP for multicast/broadcast. That not have default support in
>>WCF but you have SDK example of such.
>>Arkady
>>
>><AlexC> wrote in message
>>news:egtjn2hsvjemtbicmsh12tcj29mrt79pe5@4ax.com...
>>> I'm looking at creating a kind of collaboration /
>>> teaching environment using WCF. I want to be able
>>> to have the teacher do events that get pushed to
>>> all the student machines (like pointing at some
>>> part of a diagram).
>>>
>>> To avoid problems with the client's firewalls and
>>> NATs it seems like the best thing would be a
>>> single "permanent" TCP connection on port 80 from
>>> the clients (students) to the server (teacher).
>>>
>>> Is it possible to set this up with WCF so that the
>>> one physical TCP connection over port 80 can transmit
>>> multiple "streams" of data simultaneously? For
>>> example, it would be nice to have a lower priority file
>>> transfer flowing in either direction, while at the same
>>> time having little event packets at a high priority
>>> flowing in both directions too.
>>>
>>> How much of this can be done with WCF?
>>>
>>> Thanks,
>>> Alex
>>
>