HP StorageWorks Enterprise File Services WAN Accelerator User Manual
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Physical In-Path. The HP EFS WAN Accelerator is physically in the direct path
between the client and server. The clients and servers continue to see client and
server IP addresses. Physical in-path configurations are suitable for any location
where the total bandwidth is within the limits of the installed HP EFS WAN
Accelerator.
Virtual In-Path. The HP EFS WAN Accelerator is virtually in the path between
the client and server. This differs from a physical in-path in that a packet
redirection mechanism is used to direct packets to HP EFS WAN Accelerators
that are not in the physical path. Redirection mechanisms include Web Cache
Communication Protocol (WCCP), Layer 4 (L4) switches, and Policy-Based
Routing (PBR). In this configuration, clients and servers continue to see client
and server IP addresses.
Out-of-Path. The HP EFS WAN Accelerator is not in the direct path between the
client and the server. Servers see the IP address of the server-side HP EFS WAN
Accelerator rather than the client IP address, which might impact security
policies. An out-of-path configuration may be suitable for data center locations
where physically in-path or virtually in-path configurations are not possible.
NOTE: If you have an out-of-path configuration with failover support, you must specify the
master and backup HP EFS WAN Accelerators in the Setup: Optimization Service - In-Path
Rules page. For detailed information, see
“Setting In-Path Rules” on page 26
.
For detailed information about in-path and out-of-path deployments, see the HP
StorageWorks Enterprise File Services WAN Accelerator Deployment Guide.
When you configure in-path support, you have the following options:
Reset Existing Client Connections with Start Up. If you enable the kickoff
feature, connections that exist when the HP EFS WAN Accelerator service is
started and restarted are disconnected. When the connections are retried they are
optimized.
Generally, connections are short lived and kickoff is not necessary. It is suitable
for very challenging remote environments. For example, in an environment with
128 kbps and 1.5 seconds of latency, you might want to abort an Hypertext
Transfer Protocol (HTTP) download so that your traffic is optimized, whereas in
a remote branch office with a T1 and 35 ms round-trip time, you would want
connections to migrate to optimization gracefully, rather than risk interruption
with kickoff.
NOTE: Do not enable kickoff for in-path HP EFS WAN Accelerators that use auto-discovery
or if you do not have a HP EFS WAN Accelerator on the remote side of the network.
Enable External Traffic Redirection (Layer-4, PBR, WCCP). External traffic
redirection is only supported on the first in-path interface. The interface name
may appear as wan 0_0, wan1_0, wan2_0 and so forth, depending on how many
bypass cards you have installed in your system. The following redirection
methods are available: