Internet Money

IP Transit can be broken down into two different services, one being the advertisement of customer routes to other ISPs (Internet service providers) and the other part being advertising routes to other ISPs. By use of default routes the router can route traffic to other locations on the internet but this is not always the case. This means they are soliciting the outbound traffic from the customer towards the other networks. IPTransit could be explained as the following.

There is a number of other technical aspects to transit that you need to ask your self or provider about if you have it or need it. You have dual IP stack which is an IPv4 to IPv6 transitional technology that uses the two existing internet protocols in the operating system. One for each of the versions of IP. Each host may implement the system differently running IPv4 and IPv6 separately while another uses a hybrid system. Running a hybrid system is the most common for both the end user and on servers.

Protocols on routing need to be thought about on if your happy to have an already predetermined one way route out. this may be for cost purposes or because its the only route out of the network and have to go through someone elses router before your out onto the internet you also have Border Gateway Protocol or BGP which is the core routing protocol of the internet this works by using a table of IPs or prefixes can be used for network availability. By Autonomous system which is a collection of connected IP routing prefixes under the control of one or more network operators and so that presents a common and clearly defined routing policy to the internet. The path information is dynamically updated because BGP is a path vector protocol. If a update gets looped through the same node this is detected and discarded and this is used in other protocols to avoid infinity loops.

Peering is also available this is where networks that are separately owned and operated are interconnected to exchange the traffic between each other. The actual definition is settlement free or sender keeps all, meaning the neither of the two networks pay the other for the data that is exchanged between the two networks, this means that the revenue has to come from their customers. So many company’s now inappropriately use the work Peering when they really mean it when payment is involved. So to avoid confusion people may use settlement free peering to ensure that there is no ambiguity in what is being described or advertised.

It is via metro ethernet, that datacentres talk to each other. The internet is a great big collection of independant networks all operating from a set of standards of unique IP addressing and the use of BGP routing. You can then get relationships between these networks and are generally placed in three categories. Transit where you make payment to another network to gain internet access. Swapping and exchanging traffic for other customers is peering and is done for free and mutual benefit, or as a customer where you receive payment from another network to gain internet access. So for a network to reach any other network on the internet it must sell transit, peer directly with that network, or pay another for network transit and go round the loop until reaching the destination.