Hello, I’m Sourav Khanna, and welcome to Computer Networks and Devices part 3. Today I’m going to briefly discuss Metro Ethernet connections. Then I’m going to move on to the lease line when connections and we’re going to conclude with some common standards. With that, let’s go ahead and begin this session. Of course, I’m going to begin by discussing Metro Ethernet when connections.
What is Metro Ethernet Network Connection?
A Metro Ethernet connection is when the service provider connects to the customer’s site through an RJ 45 connector. The customer will view that when connection as an Ethernet connection while in reality, the type of connection will be dependent upon the level of service that has been purchased.
The service provider may also use a variety of different wide area network technologies behind the scenes, but the customer will always view it as being an Ethernet connection.
Metro Ethernet is commonly deployed as a wide area network technology by municipalities at the Metropolitan Area Network or man level. As in at the municipal level, it’s time for us to discuss leased lines when connections. A leased line is a dedicated circuit or connection between two endpoints used for communication.
What is the Digital Leased Line?
A leased line is usually a digital Point to Point connection. A leased line can utilize either a plain old telephone service line, a Potts line on the public switched telephone network, or it can be a fibre optic circuit provided by a telecommunications company. Leased lines tend to be more expensive for the customer, as the circuit can’t be utilized by any other entity.
So the whole cost is borne by the customer because they’re the only ones who get to use it. Most often, the speed of a leased line is limited by what the customer is willing to pay. There are some multiplexing technologies out there that can be used to increase the number of channels provided on the connection.
One of the leased line technologies that you need to know about is point-to-point protocol PPP. It is a common data link layer or layer two protocol that’s used with leased line networks, PPP can simultaneously transmit multiple-layer three protocols.
It can transmit IP and IP x and AppleTalk, all at the same time, through the use of control protocols, which are actually specific to the layer three protocol that’s being transmitted. PPP can include a feature called multi-link PPP, which allows for multiple physical interfaces to be bonded together and act as a single logical interface. This effectively increases the available bandwidth to that system.
There are different types of leased line connections.
T carrier Lines
In the United States, Japan, and South Korea, there are T carrier lines. Each t line is composed of 24 Digital Signal channels. These are often called digital signals, zero channels are DSO channels, and each channel is capable of carrying 64 kilobits per second, the 24 DSOS make up what is called a DS one channel.
In Europe, we have e carrier lines, each line is composed of 30 Digital Signal channels. These are also called DSO channels, the 30 DSL channels also make up what is called a DS one channel. When we’re talking about fibre optic speeds, we often talk about optical carrier lines or OSI lines.
The OSI data rates per channel are established by both the sonnet and SDH networking standards. Sonnet is the United States standard, and SDH is the international standard. Interestingly enough, the OSI rates are the same across the two standards, it’s possible to multiplex multiple channels into the same fibre using different methods.
The first method is dense wavelength division multiplexing DW DM, which allows for up to 32 separate channels on a single fibre cable, or you could use coarse wavelength division multiplexing, which allows for up to eight separate channels on a single fibre optic cable. Let’s conclude with common standards.
The standards I’m going to be talking about are the speeds we begin with TI lines. A T-one is composed of 24 DSO channels, which are also known as a DS one, and it’s capable of achieving speeds of up to 1.544 megabits per second. If that’s not fast enough for you, you can lease a T three line. It’s composed of 28 T-one lines.
A T three line is also known as a DS three, and it can achieve speeds of up to 44.736 megabits per second. If you’re in Europe, you might lease an E one line, an E one line which is composed of 30 DSL channels can achieve speeds of up to 2.048 megabits per second. Just as with the United States, if that’s not fast enough for you, you can lease an E three line which is composed of 16 e one-lines, which gives you up to 34.368 megabits per second speed. Well, if T-one is slower than an E one, a T three is faster than any three. For all clines.
We have the OSI one, it’s capable of 51 points 84 megabits per second in speed, and then there is the OSI three, which gives you up to 155.52 megabits per second speed. It’s becoming more common now to see OC twelve’. With those, you get up to 622.08 megabits per second.
If you want gigabit-type speed, you might consider leasing an OC 48 that gives you up to 2.488 gigabits per second in bandwidth. Currently at the top of the line is the OSI 192. That gives you up to 9.953 gigabits per second speed. So essentially 10 gigabits per second worth of bandwidth. Now that concludes this session on web technologies.
In Part Three, I briefly discussed Metro Ethernet when connections, and then I went on to discuss leased line WAN connections. And then I briefly mentioned some common standards.