System Requirements: PC Windows®
95/98/ME/NT4.0/2000/XP
Advanced Page
On this page you can manually adjust exact parameters of your connection:
MTU, TTL, MSS and RWIN, enabling/disabling auto discovery and blackhole
detection. You can also correct summary of all Windows Dial-up Networking
Registry settings manually.
You can manually change:
Maximum Transmission Unit (MTU) of a network. It is
the largest packet size that can be transferred in a frame, including
headers and trailers. It follows that if a too large packet is sent,
you get reduced performance as packets are fragmented and reassembled.
In addition, when you start, smaller packets will be saved to fill the
MTU size before being transmitted, slowing the build-up speed. By
default your computer uses Windows' defaults. Behind these you can see
industry standard MTU sizes, for example for MTU=1002 corresponds to a
terminal server. You can also enter your value of MTU by choosing the other
item.
Time To Live (TTL). The maximum time an IP packet
may exist on the network without reaching its destination, so as to
limit the number of routers it passes through.
Maximum Segment Size (MSS). It is a letter inside
the envelope, which must be smaller than MTU by at least 40 bytes, or
the size of the headers and trailers.
TCP Receive WINdow (RWIN), which is a global
setting that determines how much data gets through at the receiving
end. It actually specifies the number of bytes a sender can transmit
without receiving acknowledgements. If it is too large, more data is
lost when a packet is lost or damaged. On the other hand, transmission
will be very slow if it is too small.
PMTU Auto Discovery. Enabling this setting cause
TCP to attempt to discover the Maximum Transmission Unit (MTU or
largest packet size) over the path to a remote host. By discovering
the Path MTU and limiting TCP segments to this size, TCP is supposed
to be able to eliminate fragmentation at routers along the path that
connect networks with different MTUs.
Blackhole Detection. It enables checking of data
transfer pauses (black holes). It can improve channel utilization so
more data can be transferred in the same time interval.
Summary. You can choose automatic calculating of
all settings or correct it manually. In second case you simply choose
"Manual" item and enter needed MTU, MSS, RWIN and TTL.
There are two buttons in the bottom of the Advanced screen: Save
Settings (Saving WDNR settings to registry) and Defaults
(resetting all settings to default values). Remember, you must restart
your computer for the new settings to take effect .
