http://www.liutilities.com/tcp-udp-port/873/
The rsync application essentially uses the port 873. This application can only be found on computers that are running on the UNIX OS. Rsync is utilized in the synchronization of folders and files in computers, even when the machines are not connected or physically close to each other. This information is transferred through the Local Access Network or the LAN or the Internet. The application associated with the port runs a background process and also listens to the port 873 on the TCP protocol. This information that is passing through this port 873 flows to and fro the computer.
http://ss64.com/bash/rsync.html
In this case you will connect to a remote rsync server running on TCP port 873.
You may establish the connection via a web proxy by setting the environment variable RSYNC_PROXY to a hostname
ort pair pointing to your web proxy.
Note that your web proxy's configuration must allow proxying to port 873.
Using rsync in this way is the same as using it with rsh or ssh except that:
http://www.auditmypc.com/tcp-port-873.asp
PORT 873 – Information
- Port Number: 873
- TCP / UDP: TCP
- Delivery: Yes
- Protocol / Name: rsync
- Port Description: rsync.’rsync’
- TCP Port 873 may use a defined protocol to communicate depending on the application. A protocol is a set of formalized rules that explains how data is communicated over a network. Think of it as the language spoken between computers to help them communicate more efficiently.
- TCP port 873 uses the Transmission Control Protocol. TCP is one of the main protocols in TCP/IP networks. Whereas the IP protocol deals only with packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered on port 873 in the same order in which they were sent. Guaranteed communication over port 873 is the key difference between TCP and UDP. UDP port 873 would not have guaranteed communication in the same way as TCP.
http://www.open-e.com/site_media/dow...April_2009.pdf
There is so much more about this when you google about rsync and port 873. Ok time for me to go now see everyone next week!