UDP sockets - again

Alex Tweedly alex at tweedly.net
Wed Mar 2 17:19:34 EST 2005


Mark Wieder wrote:

>AT> (And unfortunately, Rev doesn't support either multicast or PGM).
>AT> (Actually, I think Rev doesn't fully handle broadcast - I can get it to
>AT> send to a local-broadcast address and they are received by other devices
>AT> - but I can't get Rev to receive them ... will experiment some more with
>AT> that later)
>
>This explains a lot. I had tried multicasting and decided there was
>some problem with the network configuration. Tell me about PGM -
>preferably off-list, since this is starting to get very OT, but I'm
>posting the request here in case there's other interest.
>  
>
Rev does support sending either broadcast or multicast - I can send UDP 
packets to 192.168.0.255 and also to 224.0.0.251 and receive them on my 
(on-Rev) echo server.

But it doesn't support receiving them - there's no access to raw sockets 
or to setsocketopt(). Thus, there is no way to let the system know which 
multicast groups are to be received (necessary both to get the system to 
send / respond to IGMP packets as well as to set the correct bits in the 
Ethernet driver to receive the packets).  (Not sure yet about receiving 
broadcast)

If there's anyone overhearing this and wondering what on earth multicast 
is, and wanting a techie intro  
http://www.cisco.com/warp/public/cc/pd/iosw/prodlit/ipimt_ov.htm

I'll send you PGM info off-list.

-- 
Alex Tweedly       http://www.tweedly.net



-- 
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 266.5.3 - Release Date: 01/03/2005



More information about the use-livecode mailing list