If you are seeing the 7830 traffic on client machine or between the client machine and the client side steelhead then it is expected. This traffic will not be optimized.
The way MAPI optimization works is that the client machine connects to exchange server on port 135. The exchange server tells it what port to connect back to. In your case it seems like you have limited it to port 24577 only.
Now the Steelheads tell the client machine to connect to the exchange server on port 7830 instead of 24577. This way steelhead know that the traffic is MAPI traffic and it can apply its optimization blade.
However, from the server side steelhead to the exchange server, the steelhead makes the connection using port 24577 so that the exhange server thinks that the client is connecting to it on port 24577.
Hence the one tcp connection from client machine to the exchange server which looked like
Client_IP:ephemeral_port --> exchange_server_IP:24577 now looks like
Client_IP:ephemeral_port --> Exchnage server_IP:7830 [this is intercepted by the client side sh] === Client_side_sh_IP:ephemeral_port --> Server_side_sh_IP:7800 === [server side sh makes connection to exchnage server using client's IP] Client_IP:ephemeral_port --> Exchnage server_IP:24577
HTH
