Aug 31

Hello all you IP buddies in the world!

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We are moving into a world of networking together at high speed, there is a terrific need for special people to move this to the next level.

All we hear in this world is people talking in acronyms, have we lost our very minds, do we need to talk so much that we can no longer afford the time to tell people what we really mean!

It is my intention to start on a weekly basis to bring some of these strange words that we use to communicate and see if we can find their meaning, and to this end I may need some help.

Being a site about a Subnet surfer, I feel that I will need to start with this ever so descriptive word.

So what is a Subnet:

A portion of a network that shares a common address component. On TCP/IP networks, subnets are defined as all devices whose IP addresses have the same prefix and use the same subnet mask. For example, all devices with an addresses that start with 192.168.0. (a typical home network) would be part of the same subnet. Dividing a network into smaller pieces called subnets is necessary for both security and accessibility reasons. IP networks are divided and to limit the number of devices using a subnet mask.

Most new home based routers could support around 255 devices, of which the router is 1, there is however more to it than that.

There’s a (theoretical) absolute limit of 65535 concurrent connections. So depending on what each device is running at any particular time will depend on the connections it has established with other devices either on the same network segment or through the router it is safe to assume, the maximum feasible number of devices would be somewhere near 800, to account for closing and opening connections.

This is again controlled by the subnet mask as this will limit the actual number of devices that will be issued an IP address on the segment. Another deciding factor will be the actual topology being used and the volume of traffic that will take place on the segment. Ethernet will start to fail when the traffic reaches around 60-70% of the bandwidth and the final restriction is the medium being used to transport the signals between devices. Unshielded Twisted pair cabling, a commonly used method is limited to around 100 meters between devices.

lets continue this in our next post.