WAN Technologies

WAN connection types

• DSL modem 
• Cable modem
• Satellite
• Wireless 4G LTE/ Wimax
• T1 Lines
• Fiber

More bandwidth gain

Metro Ethernet (MAN) based on ethernet used fiber optics to connect buildings together 

Easily connects with LAN

less expensive 

Synchronous Optical network (SONET): a fiber optic multiplexing standard that allows multiple channels of  communication to share a fiber optic cable

Metro Ethernet typical speeds 10 Gbps, 40 Gbps, 100Gbps

Metro ethernet is a way we coule interconnect sites within single metropolitan area network

-VSAT: very Small Aperture Terminal (VSAT)

A WAN Technology that uses small satellite dishes instead at network locations for two-communications via a satellite.

VSAT Characteristics:

• Two way satellite communication
• Satellite dish is less than 3 meters
• Useful for locations that can't have a wired connection 
• Data rates typically in the range of 56Kbps - 4 Mbps
• Data experiences more delay
• Sensitive to weather condition 

Cellular 3G/4G

G: stands for Generation

standards defined by the international  telecommunications union  radiocommunication sector

LTE Long Time Evolution is commonly offered as 4G technology

MPLS:

Multi-protocol label switching 

Makes forwarding decision based on a 20-bit label in a 32-bit header

The idea behind MPLS ( instead of having routers forward traffic based on destination IP address found in layer 3 header of a packet, we can assign labels to packets and routers within MPLS could can make forwarding decision based on label instead of ip address.

Routing based on a label rather than an ip address was originally viewed to be much more efficient way of forwarding traffic within a cloud

other advantages for MPLS 

• services provider can isolate customers traffic based on different labels 
• advance traffic engineering  that gives us a fine level of control as of how traffic is going flow through our the network
• quality of service (QoS) we can treat different types of traffic differently
•  MPLS ability to be compatible with multiple protocols

How MPLS labeling works

MPLS is going to injects its 32-bit header in between L2 and L3 headers and inside that 32-bit header we have 20-bit label (that is the label the routers look at to make its forwarding decision)

different devices on the MPLS network are going to play different rules

CPE (Customer Premise Equiment) a device at customers site that connects to an MPLS provider, ELSR (Edge label Switch Router) a device at the edge of an MPLS cloud that adds lables to traffic coming into the cloud and removes labels from the traffic leaving the cloud (note: an ELSR also know as a PE (provider edge router), LSR (Label Switch Router) a device inside an MPLS cloud that relables traffic and makes forwarding decisions based on those labels (note: an LSR is also know as P Provider Router)

its important to understand that, a packet does not keep its label thoughout the MPLS cloud every LSR hop is going to change the label  

Leased Line T1, E1 T3 and E3 Circuits

Typically, a point-to-point connection that interconnects two sites and provides dedicated bandwidth to the subscribers