Intersite link planning

Specific intersite link requirements must be met when you are planning to use IP partnership for remote copy.

If you use IP partnership, you must meet the following requirements:

TCP ports 3260 and 3265 are used by systems for IP partnership communications; therefore, these ports need to be open.
The maximum supported round-trip time between systems is 80 milliseconds (ms) for a 1 Gbps link.
The maximum supported round-trip time between systems is 10 milliseconds (ms) for a 10 Gbps link.
A 25 Gbps link cannot be used for IP replication.
IP partnerships can also support data compression. Both systems in the IP partnership must be running a software level that supports IP partnership data compression. A compression accelerator must also be installed on each system. For more information, see Configuring IP partnerships.
The amount of intersite heartbeat traffic is 1 megabit per second (Mbps) per link.
The minimum bandwidth requirement for the intersite link is 10 Mbps. However, this requirement scales up with the amount of host I/O that you choose to do. Figure 1 describes the scaling of host I/O.
Figure 1. Scaling of host I/O

The equation that can describe the approximate minimum bandwidth that is required between two systems with < 5 ms round-trip time and errorless link follows:

Minimum intersite link bandwidth in Mbps > Maximum(Minimum Link Bandwidth of 10Mbps , Required Background Copy in Mbps + Maximum Host I/O in Mbps + 1 Mbps heartbeat traffic)

Increasing latency and errors results in a higher requirement for minimum bandwidth.