mooseshoes wrote:

> All:
>
> I am trying to figure out why a client can't see UDP packets generated from
> my Multicasting server. Here are the facts:

The first fact you need to understand is that most ISPs still do not support
multicast.

> Server-
>
> - Mandrake Linux v9.1 OS
> - Perl UDP Socket
> - DSL/ppp0 interface to Internet

Second is that of those ISPs that DO support multicast only support it to their
broadband customers, so dialup customers cannot access multicast.

> - Destination, 234.x.x.x:PortB
> - TTL = 255
>
>
> Client (across Internet)-
>
> - Java app./socket
> - Linksys DSL router (DMZ - no security settings for testing purposes)
> - DSL connection to Internet
> - Multicast Group added through Java app.
>
> Verify
>
> - Ethereal sniffer on both server and client
> - Packet Length = 104 bytes
> - TTL verified
> - frame captured - sent 88 bytes from 207.x.x.x:PortA to 234.x.x.x:PortB
>
> The client can't see the messages!

You both need to check for multicast support with your ISP and either change
ISPs to get multicast support or use a multicast tunnel.

> Any suggestions of what to try would be greatly appreciated.
>
> Thank you in advance,
>
> Moose

--
Phil Frisbie, Jr.
Hawk Software
http://www.hawksoft.com

Phil:

Thank you so much for your response. Please see my answers below.

<snip>

> The first fact you need to understand is that most ISPs still do not
support
> multicast.

<<< I will check with SBC Yahoo! DSL

<snip>

> Second is that of those ISPs that DO support multicast only support it to
their
> broadband customers, so dialup customers cannot access multicast.

<<< I'm assuming then that any ISP, regardless of being broadband, dialup or
otherwise would not carry
the multicast message of the host ISP. That model is clearly broken for the
Internet.

<snip>

> You both need to check for multicast support with your ISP and either
change
> ISPs to get multicast support or use a multicast tunnel.

<<< I'd like to learn more about multicast tunneling. Can you point me
towards some online sources? I will, of course, do my own research, but if
you know of any good documentation off hand, that would be helpful.

Thank you again.


> Phil Frisbie, Jr.
> Hawk Software
> http://www.hawksoft.com
>

On 28 Aug 2003 21:48:59 GMT, Mooseshoes <mooseshoes@gmx.net> wrote:
[snip]
>
>> Second is that of those ISPs that DO support multicast only support it to
> their
>> broadband customers, so dialup customers cannot access multicast.
>
><<< I'm assuming then that any ISP, regardless of being broadband, dialup or
> otherwise would not carry
> the multicast message of the host ISP. That model is clearly broken for the
> Internet.
>

I'd suggest its not the multicast model itself thats broken,
rather its (non)implementation by most ISP's.

chris