To avoid network choking or congestion in your computer network, you will have to maintain all devices in the network, conflict-free and malware-free.
Switches/Hub: Use good switches or hubs in the network. However, using switches or hubs with suitable bandwidth capacity is as important as using good ones.
Network adapters and others devices, for your network, depending on the speed of systems:
Network Cables: Use network cables which can handle data packets based on switch/hub speed. Ex: If we use Gigabyte switch with cat5 cables choking will happen in network, because cat5 cable cannot have more than 100mbps data transfer. So its better to use network cables based on switch/hub speed.
Network adapters: Use network adapters (Lan Cards), which are suitable for your network. Like if your network is with gigabyte switches and cat6 cables, use only gigabyte network adapters, otherwise systems cannot receive the data packets coming from switch/hub.
Malware-free: Always use a good antivirus software with latest updates for scanning your systems. Because some malware also causes network choking. It gets downloaded in to the system and creates traffic in the network.
Check your switches and network adapters settings – is it configured properly or not. Bad Switches/hubs/network adapters are also causes for network choking.