Upgrade to higher-speed switches and NICs
Use full-duplex links
Enable link aggregation
Reduce broadcast and multicast traffic
Segment the network with VLANs
Optimize MTU and jumbo frames where supported
Remove bottlenecks in routers, firewalls, and uplinks
Balance traffic across multiple paths
Prioritize critical traffic with QoS
Replace congested hubs with switches
Use faster cabling and proper cable categories
Minimize packet loss and retransmissions
Tune TCP window sizes and offload features
Load balance servers and services
Place devices closer to the data source
Cache frequently accessed data locally
Schedule large transfers during off-peak hours
Monitor utilization and identify underused links
Eliminate duplex mismatches
Upgrade outdated network hardware
Consolidate inefficient small flows where possible