Multicasting using TCP/IP for Multiple clients

[madd]

Hello

 i have been watching in Find example Vi's in labview  there is are UDP multicasting receiver and sender Vi's Is there

any available for TCP/IP for multiple clients. or any other way to broadcast the messages from server to many clients 

Regards

[craigc]

Definitely not as simple with TCP I have used a Publisher / Subscriber type approach before whereby one PC handles all the incoming connections and lists available services etc (Publisher) to which many Subscribers can ask for the data to be broadcast to them.

An even easier way is to use Datasocket or maybey even a shared variable which I have not used but looks suitable for suach a task.

Craig

[altenbach]

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madd wrote:

 i have been watching in Find example Vi's in labview  there is are UDP multicasting receiver and sender Vi's Is there

any available for TCP/IP for multiple clients. or any other way to broadcast the messages from server to many clients 

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OK, you are possibly confusing things. UDP is part of TCP/IP. Could it be you are trying to multicast using TCP?

This is not possible. TCP is a connection based protocol, meaning any connection is established between exactly two partners, starting out with the three-way handshake, the data transmission and acknowledgments, and the connection tear down. This ensures complete delivery verification of all communications at the expense of the protocol overhead. (similar to a classic phone connection between two people: First you verify the right person picks up, then you talk, then say goodbye)

UDP is a connectionless protocol, meaning any packets are simply placed on the wire and the protocol itself does not ensure any verification of delivery (similar to e.g. a radio broadcast). Any two-way communication needs to be done by the program, e.g. the receiver could send another UDP packet back to notify the sender that a packet was received.

Broadcast and multicast packets must be connectionless. There is no way around it. You can use UDP for broadcasts and TCP for for data at the same time in the same program, but you cannot combine the two into a single connection. They don't mix.

Maybe I misunderstood. If I did, please clarify what you had in mind. More details!

[madd]

Hello

i have another question. Can i use TCP/IP and UDP to transfer data in the same vi(server sending UDP and TCP/IP

data in same VI).In fact i have tried it.i have used multicast sender  and TCP/IP Data server in a same vi on my server

side and multicast receiver and TCP/IP Data Client in one vi on my client side, then i run my server first and client

second both UDP and TCP/IP data is received seemingly (as i can see sine graph for TCP/IP and multicast data send for UDP). But there is a software WireShark to sniff packets on ethernet port, when i use it to capture data UDP seems to be fine (as i can see the data i am sending from TX side) But when i see TCP/IP data the checksum gives Incorrect Status and retransmission request is repeated due to which My client side cor2duo processor PC gives 100% usage. why is this CheckSum status Incorrect.....? Am i receiving true data or not 

Regards