Parabolic or dish antennas
This is where the real power is! Parabolic dish antennas put out tremendous gain but are a little hard to point and make a connection with. As the gain of an antenna increases, the antenna’s radiation pattern decreases until you have a very little window to point or aim your dish correctly. Dish antennas are almost always used for a point to point system for long haul systems. The Parabolic Dish antennas work by focusing the power to a central point and beaming the radio’s signal to a specific area, kind of like the adjustable reflector on a flashlight. These antennas are highly focused and are the perfect tool if you want to send your signal a very long distance.
Tag Archives: reference
AdditionalResources/Repositories/RPMForge
The default RPMforge repository does not replace any CentOS base packages. In the past it used to, but those packages are now in a separate repository (rpmforge-extras) which is disabled by default.
You can find a complete listing of the RPMforge package packages at http://packages.sw.be/
via AdditionalResources/Repositories/RPMForge – CentOS Wiki.
The rpm at this link allows for yum to see the additional packages — such as alpine and perhaps others that were missing in the base.
Load balancing – LVSKB
In computing, load balancing is a technique used to spread work load among many processes, computers, networks, disks or other resources, so that no single resource is overloaded.
Load balancing can also be considered as distributing items into buckets:
- data to memory locations
- files to disks
- tasks to processors
- packets to network interfaces
- requests to servers
Its goal is even distribution.
RFC 3261 – SIP: Session Initiation Protocol
This document describes Session Initiation Protocol (SIP), an application-layer control (signaling) protocol for creating, modifying, and terminating sessions with one or more participants. These sessions include Internet telephone calls, multimedia distribution, and multimedia conferences.
The TCP Datagram
push flag (1 bits)
The push flag tells the receiving end of the tcp connection to “push” all buffered data to the receiving application. It basically says “done for now”.
via The TCP Datagram.
This would be the PSH flag that I needed to look up and found this site which makes for a good reference.
Transparent web proxy – DD-WRT Wiki
Running a transparent proxy server on your network can be used for more advanced content filtering of web pages for environments such as a school or library (where in some locales, filtering is required by law) or as a way to protect children in the household.
This guide will help you enable a transparent proxy server on your network by having your WRT54G router forward all traffic to the proxy server automatically.
Linux Firewalls Using iptables
Quick HOWTO : Ch14 : Linux Firewalls Using iptables – Linux Home Networking.
This site was also linked here last May but is so useful I needed to bring it to the top again. Here’s a pertinent figure that describes the iptables process that I seem to need to reference all the time when editing the iptables config file.
20 Linux System Monitoring Tools Every SysAdmin Should Know
List of router or firewall distributions
This is a list of operating system distributions designed for use as the operating system of a machine acting as a router and/or firewall.
List of router or firewall distributions – Wikipedia, the free encyclopedia.
XMPP Technologies Overview – The XMPP Standards Foundation
XMPP is the Extensible Messaging and Presence Protocol, a set of open technologies for instant messaging, presence, multi-party chat, voice and video calls, collaboration, lightweight middleware, content syndication, and generalized routing of XML data.
XMPP was originally developed in the Jabber open-source community to provide an open, secure, spam-free, decentralized alternative to the closed instant messaging services at that time. XMPP offers several key advantages over such services:
via XMPP Technologies Overview – The XMPP Standards Foundation.