552 Implementing the IBM Storwize V7000 with IBM Spectrum Virtualize V8.2.1
11.8.3  IP Partnership and data compression
When creating an IP partnership between two systems, you can specify whether you want to 
use the data compression or not. When enabled, IP partnership compression compresses the 
data that is sent from a local system to the remote system and potentially uses less 
bandwidth than with uncompressed data. It is also used to decompress data that is received 
by a local system from a remote system.
Data compression is supported for IPv4 or IPv6 partnerships. To enable data compression, 
both systems in an IP partnership must be running a software level that supports IP 
partnership compression (V7.7 or later).
To fully enable compression in an IP partnership, each system must enable compression. 
When compression is enabled on the local system, data sent to the remote system is 
compressed so it needs to be decompressed on the remote system, and vice versa.
Although IP compression uses the same RtC algorithm as for volumes, there is no need for a 
RtC license on any of the local or remote system.
Replicated volumes using IP partnership compression can be compressed or uncompressed 
on the system because there is no link between volumes compression and IP Replication 
compression: 
/SM590000Read operation decompresses the data
/SM590000Decompressed data is transferred to the Remote Copy code
/SM590000Data is compressed before being sent over the IP link
/SM590000Remote system remote copy code decompresses the received data
/SM590000Write operation on a volume compresses the data
11.8.4  VLAN support
Starting with V7.4, VLAN tagging is supported for both iSCSI host attachment and IP 
replication. Hosts and remote-copy operations can connect to the system through Ethernet 
ports. Each traffic type has different bandwidth requirements, which can interfere with each 
other if they share the same IP connections. VLAN tagging creates two separate connections 
on the same IP network for different types of traffic. The system supports VLAN configuration 
on both IPv4 and IPv6 connections.
When the VLAN ID is configured for IP addresses used for either iSCSI host attach or 
IP replication, the VLAN settings on the Ethernet network and servers must be configured 
correctly to avoid connectivity issues. After the VLANs are configured, changes to the VLAN 
settings will disrupt iSCSI and IP replication traffic to and from the partnerships.
Note: The Bandwidth setting definition when the IP partnerships are created changed 
in V7.7. Previously, the bandwidth setting defaulted to 50 MiB, and was the maximum 
transfer rate from the primary site to the secondary site for initial sync/resyncs of 
volumes.
The Link Bandwidth setting is now configured by using megabits (Mb) not MB. You set 
the Link Bandwidth setting to a value that the communication link can sustain, or to 
what is allocated for replication. The Background Copy Rate setting is now a 
percentage of the Link Bandwidth. The Background Copy Rate setting determines the 
available bandwidth for the initial sync and resyncs or for GM with Change Volumes.