HP StorageWorks 4000/6000/8000 .HP StorageWorks SAN Design Reference Guide, Pa - Page 274

Continuous Access SVSP V2.1 This section describes the Continuous Access SVSP V2.1 asynchronous data replication specifications and the supported minimum and maximum transmission rates when using the SVSP VSM servers. Table 137 lists the minimum network QoS requirements when using SVSP V2.1. Table 137 SVSP v2.1 inter-site network requirements for long distance gateways Specification Description Bandwidth Can be shared, but doing so may prevent you from performing replication MTU of the IP network 1,500 bytes Maximum latency1 150 ms IP network delay one-way or 300 ms roundtrip Average packet-loss ratio2 Must not exceed 0.5% averaged over a 5-minute window Latency jitter3 Must not exceed plus or minus 10% over a 5-minute window 1Pre-existing restriction 2A high packet-loss ratio indicates the need to retransmit data across the inter-site link. Each retransmission delays transmissions queued behind the current packet, thus increasing the time to complete pending transactions. 3Latency jitter is the difference between the minimum and maximum values, and indicates how stable or predictable the network delay. The greater the jitter, the greater the variance in the delay, which lowers the performance predictability. NOTE: Applications typically require more than the minimum bandwidth to meet throughput or initial full copy requirements. For example, at 10 Mb/s it, could take up to two weeks to copy 1 TB of data, longer if the average available bandwidth is less than 10 Mb/s. 274 SAN Virtualization Services Platform