Good day firends
I am trying to write app for my echosounder humminbird helix 9 to live receive data from it.
I have connected it by router and using wire shark i found that it streams data by multicast :
side scan row data stream, gps stream, sonar stream. Please find attached
Up to now i find out how to receive frames to my app, but i can not manage to take over multi cast stream read.
For example to read gps data 
Do you have any clue how to connect to multi cast stream and take data from it?. Like from above screen gps data .
Best regards
If any body have an idea how to manage this problem ?
I've been messing around with the same stuff that you are.
What i've discovered thus far is that there are 2 ways that these units share data on the network. For more simple data sources (GPS), you need to estabilish a TCP connection described by the SLP exchanges you are seeing broadcast.
For sonar data, you need to send a TCP message to the service listening on a particular port to tell the unit to start multicasting data. You'd then be able to see UDP packets if you open up a socket on the port specified in the SLP exchanges (joining the multicast address also specified by the SLP exchanes).
Essentially step one is to get a basic SLP/SRVCLOC client/user agent set up and then go from there.