STM SatLink VSAT - HTTP Acceleration (HTTPA)

SatLink VSAT User Guide
Publication no. 101557
Rev 14.1.1-2
Copyright 2006-2012 – STM Group, Inc.
Page 99 (182)
Parameters
Description
Maximum Connections
Shows the maximum number of TCP connections that the VSAT PEP client
can handle simultaneously.
Current Connections
Indicates the number of TCP connections that is handled by the VSAT PEP
client at the moment.
Total Connections
Indicates the total number of TCP connections that has been handled by the
PEP client since the PEP functionality was enabled.
Trans Connections
Once the number of connections exceeds the threshold Maximum Connections
(i.e., 250 connections), the additional new connections are established without
performance enhancement techniques being applied to these. The parameter
Trans Connections indicates the number of connections that are passed
―transparently‖ through the VSAT without PEP due to the Maximum
Connection threshold being exceeded.
Failed Connections
Indicates the number of connections that were attempted established, but did
not succeed.
Table 15: Parameters Displayed When Typing ip pep show
18.3 HTTP Acceleration (HTTPA)
HTTP acceleration (HTTPA) can be enabled in the SatLink 2900, 2000, 1910, and 1000 Revision 2.x.
HTTPA is an embedded Intercepting Proxy Cache (IPC) that pre-fetches objects found by reference in
accessed web pages. The internal VSAT DNS server is used to resolve the URLs. Pre-fetching speeds up
web browsing over the satellite link through the use of parallel connections to several servers. HTTPA
does, to some extent, cache objects to reduce response time. This is especially useful in a multi-user
environment.
HTTPA generally improves the user experience when rendering web pages over the satellite link. Note
that the improvement may differ significantly between web pages, as these typically have different sizes,
complexities and structures. If an object requested by the HTTP client is found in the SatLink VSAT‘s
internal web-cache, the object will be delivered immediately.
When the VSAT is licensed to support HTTP acceleration, the function can be enabled and disabled. By
default, the HTTP accelerator is disabled. HTTP acceleration operates in the context of TCP acceleration.
When enabling HTTP acceleration, TCP acceleration is also enabled in the currently configured TCP
acceleration mode; see section 18.2.
To enable HTTPA:
# ip pep enable httpa
To disable HTTPA:
# ip pep disable httpa