TCP
was never designed to be transmitted over a congested radio network
such as GPRS, with the result that data flow is inefficient and throughput
is greatly reduced. The throughput achieved will be much less than the
theoretical maximum of your terminal even when used in optimum conditions.
For example a three slot handset with a theoretical maximum of 43kbps
will only achieve an average throughput of 20-30kbps.
The
best place for a TCP Optimization box is on your operators GPRS network,
but if you are running IPSEC virtual private networks you will not be
able to benefit from the optimization, as the IPSEC prevents any changes
to the data stream. In this case private optimization servers may be
located behind the VPN firewall.
HTML
Optimization
The download of web pages may be greatly increased
by combining a number of techniques
On-the-fly
recompression of graphics - a slight reduction in quality may be
observed
Removal
of unnecessary HTML commands/comments etc.
Reordering of content to display words first
Recompression
of any sounds or streaming audio
HTML optimization is best done alongside
the TCP optimization on the core GPRS network, but if you are using security
encryption such as VPN, then you will need to invest in your own optimization
box as the GPRS core network no longer has access to your data.
E-mail
Optimization
E-mail
receive: While it may be unacceptable to change the text part of an e-mail,
any attachment may be compressed to speed download and presented either
as a CAB or ZIP file. To utilise this will require support by your ISP
or GPRS supplier, or by a third party service provide where you can redirect
your emails from you ISP to the optimization POP server.
E-mail send: It is
usually up to the user to compress any attachment using a program such
as WINZIP to efficiently compress documents.