HP StorageWorks Enterprise File Services WAN Accelerator Deployment Guide (November 2005)

30 3 - LOGICAL IN-PATH NETWORK DEPLOYMENTS
 Layer-4 Switch. You enable Layer 4 switch (or server load-balancers)
support when you have multiple HP EFS WAN Accelerators in your
network to manage large bandwidth requirements.
 Hybrid. A hybrid deployment is a deployment in which the HP EFS
WAN Accelerator is both in-path and out-of-path. A hybrid deployment
is useful where the HP EFS WAN Accelerator must be referenced from
remote sites as an out-of-path device (for example, to avoid mistaken
auto-discovery or to bypass intermediary HP EFS WAN Accelerators).
For detailed information, see Chapter 4, “Out-of-Path Network
Deployments.”
 Policy-Based Routing (PBR). PBR enables you to redirect traffic to an HP
EFS WAN Accelerator that is configured as an out-of-path device. PBR
allows you to define policies to route packets instead of relying on routing
protocols. You define policies to redirect traffic to the HP EFS WAN
Accelerator and policies to avoid loop-back. For detailed information, see
Chapter 6, “Policy-Based Routing Deployments.”
 WCCP. WCCP was originally implemented on Cisco routers, multi-layer
switches, and web caches to redirect HTTP requests to local web caches
(Version 1). Version 2, which is implemented on HP EFS WAN
Accelerators, can redirect any type of connection from multiple routers or
web caches. For example, if you have multiple routers or it there is not a
logical place for the HP EFS WAN Accelerator, you can place the HP EFS
WAN Accelerator to be logically in-path through the router so that they
work together. Typically, you configure WCCP on the client-side HP EFS
WAN Accelerator. For detailed information, see Chapter 7, “WCCP
Deployments.”
In-Path, Load Balanced, Layer-4 Switch
An in-path, load-balanced, Layer-4 switch deployment serves high traffic
environments or environments with large numbers of active Transmission
Control Protocol (TCP) connections. It handles failures, scales easily, and
supports all protocols.
When you configure the HP EFS WAN Accelerator using a Layer-4 switch, you
define the HP EFS WAN Accelerators as a pool where the Layer-4 switch
redirects client and server traffic.
Only one WAN interface on the HP EFS WAN Accelerator is connected to the
Layer-4 switch and the HP EFS WAN Accelerator is configured to send and
receive data through that interface.