TIP: Make your LAN more friendly to Streaming

[funchords]

You know the problem -- you're watching a streaming video when someone -- perhaps even you -- decides to back up your entire MP3 collection over the LAN. Suddenly, the streaming video starts to stutter and the whole thing becomes unwatchable.

Bandwidth is consumed up to its maximum. But, at maximum, the system begins to bog down because the processor utilization goes up, someone else jumps online -- and maximum begins to drop. When that happens, everything slows down equally to accomodate the new conditions -- and your streaming video is slowed with it.

On a LAN, the internet is not the biggest culprit -- at least not yet. Ironically fortunate for us, the tiny amounts of bandwidth our cable and telephone companies provide do not saturate the LAN. The biggest user is computer-to-computer transfers of files -- in Windows this is usually done over port 139 for "File and Printer Sharing."

I have implemented a free solution in my home that I'd like to share. The upside is that the network transfers are tamed, but still plenty fast. The downside is that it doesn't seem to adjust dynamically, even when you have bandwidth to spare. (The docs suggest that there is a way for lower priority packets to yield to higher priority packets, but this feature -- if it works for all -- doesn't work for me. So basically, this setup just slows down NetBios transfers. Documentation is included should you want to experiment.)

To set this up:

1. Download version 0.2.8 of the free WinTC Traffic Controller from http://hp.vector.co.jp/authors/VA027031/wintc/.

2. Read the install file enclosed and install it. Make a second copy of the original wintc.conf file so that you can go back to it if you want to make changes or enhancements.

3. For your wintc.conf file, use this:

# wintc.conf to slow down your LAN speed by throttling
# your NetBios connections
#
# the 768KBps here is based on my 802.11g wireless LAN's 
# top throughput of around 2700 KB.  This leaves lots of 
# room for other network uses such as streaming, 
# downloading from the internet, playing online games.
#
# If you have an all-wired LAN, you can raise the number.
# 

define_flow = flow-intranet 768K prio=3 limit=yes
define_filter = srv-netbios srcport=139
assign_filter = srv-netbios flow-intranet

#EOF

4. Install this on all of the computers in your LAN.

This is a good "set-it-and-forget-it" solution and it appears to be heading toward a decent implementation of QoS prioritization and Traffic Shaping.

-------------------

But, let's say you only transfer files across the LAN once in a very great while, and you don't want to slow your LAN-to-LAN transfers down permanently. Here is a different solution to that problem:

Nullsoft's free NSCopy, which you can find at http://www.nullsoft.com/free/nscopy/ is an over-the-LAN file copying application with a gas pedal -- you can set it for the speed you want, even speeding it up and slowing it down mid-copy!

It's great for those huge jobs that take 18 hours -- start it at full speed when you go to work, in the evening, slow it down to half-speed so you can watch Beyond TV Link, and then bring it back up to full speed when you go to bed!

-- Robb Topolski