Posted on in system_administration
As we have throughout the
TCP Performance Tuning
series, we're going to make sure RFC 1323 Window Scaling is enabled and increase
our send and receive window size to 1 MB. The ndd command is the Solaris
equivalent of sysctl in FreeBSD/Linux/Mac OS X.
sudo ndd -set /dev …Posted on in system_administration
Because Darwin is BSD-based, it's no surprise that Mac OS X TCP Performance Tuning is very similar to FreeBSD TCP Performance Tuning. It is no longer necessary to enable RFC 1323 TCP Extensions (in fact, the option to do so is gone). Also, we'll set the TCP send and receive …
Posted on in system_administration
If you have been following our
TCP Performance Tuning series, you'll know
that we want to enable RFC 1323 Window Scaling and increase the TCP window size
1 MB. To do this, we'll add the following lines to /etc/sysctl.conf and issue
sudo sysctl -p to apply the changes …
Posted on in System Administration
In TCP window scaling and broken routers posted in July of 2004, LWN.net's corbet points out that certain routers are setting the RFC 1323 window scale to 0. This effectively sets the TCP window size for the transmission to the minimum value and greatly inhibits performance. As corbet notes …
Posted on in System Administration
The original TCP specification included a window size no larger than 64 KB. This limitation was introduced by the 16 bit header that specified window size. To achieve the recommended 1 MB window size, RFC 1323 TCP extensions must be enabled. The rest of this post is a somewhat detailed …
Posted on in voice
Trying to debug an <acronym title="Asterisk Gateway Interface">AGI</acronym> in Asterisk can be a frustrating experience. The main problem is that STDERR only outputs to the terminal Asterisk was started from. In most cases, this means the terminal is the server console. If your Asterisk server is sitting …
Posted on in system_administration
Note: Stanislav Shalunov wrote an excellent article on TCP over WAN Performance Tuning and Troubleshooting. In this series of articles, I want to summarize his findings and provide tuning suggestions for popular operating systems.
Most operating systems today ship with TCP stacks optimized for either LAN (high speed, low latency …
Posted on in System Administration
Note: Now that Google is hosting email domains for free, it has become an interesting alternative for both new and old domains. As always, I've changed the names to protect those affected.
Transitioning a domain to Google can be an arduous task. Once you have set up the domain with …
Posted on in Software
XHTML Character Entity Reference
Digital Media Minute's Jim Rutherford has developed an invaluable reference in his XHTML Character Entity Reference. With this reference in hand, I can finally ditch all my little notes about copyrights, trademarks, and cedillas. Here's an explanation of how the page works in Jim's own …
Posted on in Networking
Deciding whether to use <acronym title="Remote Authentication Dial-In User Service">RADIUS</acronym> or <acronym title="Terminal Access Controller Access Control System Plus">TACACS+</acronym> for <acronym title="Authentication, Authorization, Accounting">AAA</acronym> functionality on a Cisco-based network seems straight-forward. After all, if the network uses Cisco, shouldn't the AAA …
Posted on in Graphics Design
Important commands: sips
A few folks have asked me where I got the nice looking Software Update icon for my post regarding Apple's Security Update 2007-004. First, let me say, "Thanks for noticing!" Second, let me point out that Steve Jobs will probably be knocking on the door of the …
Posted on in System Administration
Sam Varshavchik with the Courier Mail Server project announced updates for all their major software packages including courier-imap, courier-authlib, and maildrop, in addition to the Courier MTA. The major fix common to most packages appears to be the plugging of a memory leak which only came into play once a …
Posted on in System Administration
Posted on in System Administration
Posted on in Software
One of the features of Firefox 2 is Session Restore. By default, if Firefox needs to restart for an update (or crashes), it will restore your session to the state it was in at the time of restart. That means your tabs and windows will be just like you left …
You've probably been using 