Apple releases Broadband Tuner 1.0 this week. It allows you “to take full advantage of very high speed Internet connections that have a high latency (5 Mbps or greater). This is especially good for Mac users on Verizon’s FiOS Internet that may be experiencing slower speeds than FiOS allows.

The Broadband Tuner allows you to take full advantage of very high speed Verizon FiOS based Internet connections that have a high latency. The installer tweaks some system parameters.

There is an optional uninstaller that can be used to restore the settings that were in effect at the time just before the system parameters were changed.

What does the Broadband Tuner do exactly?
The installer increases the default values for the size of the TCP send and receive buffers. With larger buffers more data can be in transit at once. A start-up configuration file is also updated so that these changes will persist across restarts.

The system parameters are sysctl variables that are set as follows:
net.inet.tcp.sendspace: 131072
net.inet.tcp.recvspace: 358400
kern.ipc.maxsockbuf: 512000

This change has a system wide effect and is applied even if the network is not high speed connection with a high latency, with the exception of modem connections for which the system uses small default TCP buffer sizes.

You can check your connection’s latency entering the following command in the Terminal (found in Applications -> Utilities),

ping a.root-servers.net

then pressing return

If you see a relatively high response time (above 80 milliseconds), you will most likely see benefits from the patch. Use Control + Z to end ping.

I do not have a Verizon FiOS connection at home as of yet. It should be available in my town in the next coming months, as Verizon trucks are everywhere here pulling fiber. I will switch as soon as it becomes available.

I tried it on my Cable Modem connection at home and it does not seem to make much of a difference for my connection, but your experience may be different. I have tested Macs on Verizon FiOS and experienced no problems. But there have been some people reporting less than advertised speeds. See my story on Verizon FiOS on this weblog from July 2005, “Verizon FiOS and the Macintosh.” I am was happy to see Apple address this.

Users with satellite connections, which generally suffer from long ping times, should also see significant benefit. Latency for satellite Internet connections is typically 500-600ms, compared to 18-100ms for DSL and cable modem access. This delay can cause problems for latency sensitive applications such as VoIP (Voice over IP) videoconferencing, and online games. Although, not as important for web surfing, downloading files, or streaming audio or video. Users have reported even web pages loading faster after applying this patch.

    | Tags: FiOS, troubleshooting, verizon