Calibre Port Configuration for Calibre MTflex “-hyper remote”

Key Considerations:

• Open TCP/UDP Traffic: TCP and UDP traffic should not be blocked by internal firewalls.
• RTT Warnings: Round-trip time (RTT) warnings or errors in the Calibre log file are often an indication that TCP/UDP traffic is being blocked by internal firewall rules.

Recommended Port Configuration: Selecting Sufficient Ranges

1. Primary and Remote Port Range: TCP and UDP ports in the 5000-65535 range must be open to support Calibre MTflex’s peer-to-peer communication. Our testing has shown that opening only the range of temporary or private ports 49152-65535 may not suffice, and still introduce RTT issues. Log file warnings and errors during MTflex initialization or remote data system initialization indicate insufficient available TCP or UDP ports. 
2. Adjustments Based on Configuration: The exact number of required ports will vary depending on the Calibre run mode, compute resources, and the specific configuration used.
3. Firewall and User Limits:

• To ensure performance, administrators should verify that system-level configurations support the high process and descriptor limits required by MTflex.

For instance, warnings suggesting an increase in the max user processes and descriptors limits indicate that system resources may be a bottleneck under high loads.

• Also, users need to turn off all firewall rules on internal switches and hosts in the DMZ for their HPC runs.

Troubleshooting and Assistance

If you experience issues with -hyper remote runs, such as RTT warnings or other difficulties:

• Consult your network administrator to review and fine-tune port configurations.
• Reach out to your Calibre customer support team for further guidance while ensuring compliance with your organization’s security policies.