What are the differences between Point to Point vs Point to Multipoint Communication Schemes? When do you choose Point to Point and when - Point to Multipoint?
Of course, everything comes down not only for a type of services and network you are planning and building (Is it LAN, WAN or MAN?) and also it’s type – Access, Core, Last Mile?
Different types of transmissions in the network may be applied depending on the amount of nodes – senders and receivers. The relationship that has single transmitter as well as single receiver is called point-to-point. WAN connection between two offices located in different cities is the best example of point-to-point transmission. It is applicable since there is only one sender (office A in city A) and one receiver (office B in city B).
Figure 1: Point to Point simplified depiction. It can be wire, or wireless, so do not stick to “waves” too much, it is a formal representation.
So, real life example from our, Fiberbit’s optical communication world can be for example 2 Gigabit Media Converters, working in point to point – like this:
Another type of transmission is point-to-multipoint. As it might be clear from the name, single transmitter is sending data to multiple receivers. Depending on identification of the receivers there might be two types of point-to-multipoint.
Figure 2: Point to Multpoint simplified depiction. It can be wire, or wireless, so do not stick to “waves” too much, it is a formal representation.
Now, again, using examples from fiber optic communication field, let’s apply here EPONconcept, then it looks like this:
Now, you can see that OLT stands in a center premises and signal get’s send down to many receivers in this case – ONU’s.
If the receivers are unidentified, the transmission would be broadcast. broadcast transmission is common for media, such as radio stations that transmit radio waves not depending on amount of receivers. This type of transmission is used to identify nodes in the network, when it is undiscovered. It can be used for wired and wireless types of networks. Special scenario is multicast, and we describe that in a special article related to Layer 2 in EPON networks, and it discusses a multicast concepts and IGMP for IPTV over PON.
In scenario when network is discovered and all the recipients defined, it would be a nonbroadcast transmission. Such as single message sent to all workstations in the LAN of the office.
