Need to help my team with packet creation and processing with MD5 Hash algorithm

My development team is working on a trading system and they are stuck at the level of creating a packet and sending it over TCP Protocol to the server. They have embedded the structure and added the necessary MD5 hash As well. But something is going wrong. I want an expert who can guide us with this scenario.

We are ready for Hourly rates and you will also get a chance to work on our bigger projects.

We need it ASAP.

Thanks