text: Global Mirror allows you to relax constraints on system requirements at the cost of using 
  asynchronous replication, which allows the remote site to lag behind the local site. Choice of 
  the replication type has major effects on all other aspects of the copy services planning. 
  
  The use of Global Mirror and Metro Mirror between the same two clustered systems is 
  supported. 
  
  If you plan to use copy services to realize some application function (for example, disaster 
  recovery orchestration software), review the requirements of the application you plan to use. 
  Verify that the complete solution is going to fulfill supportability criteria of both IBM and the 
  application vendor. 
  
  **Intercluster link**
  The local and remote clusters can be connected by FC, FCoE, or IP network. The IP network 
  can be used as a carrier for FCoIP solution or as a native data carrier. 
  
  Each of the technologies has its own requirements concerning supported distance, link 
  speeds, bandwidth, and vulnerability to frame or packet loss. For the most current information 
  regarding requirements and limitations of each of supported technologies, see this website. 
  
  The two major parameters of a link are its bandwidth and latency. Latency might limit 
  maximum bandwidth available over IP links, depending on the details of the technology that is 
  used. 