Network architecture

In terms of hardware requirements MPLS utilizes three main components:
• Ingress Label Edge Router (LER): Provides insertion of the Labels
• Egress Label Edge Router (LER): Strips the labels and forwards the IP data as necessary
• Label Switch Router (LSR): Essentially manages the labeled packets, including swapping old labels with new labels (as it passes the label to the next router) and a host of other management functions.

In terms of hardware requirements MPLS utilizes three main components:
• Ingress Label Edge Router (LER): Provides insertion of the Labels
• Egress Label Edge Router (LER): Strips the labels and forwards the IP data as necessary
• Label Switch Router (LSR): Essentially manages the labeled packets, including swapping old labels with new labels (as it passes the label to the next router) and a host of other management functions.

Label Switched Path (LSP). This is a unidirectional tunnel created between any two LER devices. LSP must be used in order to forward any MPLS data.

Figure 1. An MPLS cloud has data enter through an Ingress Edge Router (LER), travel through the Label Switch Router (LSR) and then back to an Egress Edge Router to its next destination.

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Perhaps an MPLS network can be best viewed as a cloud. Data enters the cloud through the Ingress Edge Router, travels through the Label Switch Router and then back out to the Egress Edge Router onto to its next destination. Figure 1 provides an example.

Deploying MPLS in broadcast

There are several characteristics that set MPLS apart from an IP-based network, particularly as a means to connect groups of radio stations, both regionally and nationally. Here are a few reasons to look at it:
• MPLS supports bi-directional data paths.
• Properly designed MPLS networks are very scalable and fault tolerant.
• Easy to configure.
• Supports any protocol, thus allowing the ability to carry several different infrastructure requirements over a single network i.e. voice and data traffic. Operational and capital expenses are significantly reduced.
• Priority levels can be assigned to specific types of data.
• Network latency is less than traditional IP routing.
• No need to utilize channel banks i.e. DS1,2,3,etc. Bandwidth is allocated based on need and priority. MPLS networks are well suited to handle the demands of the largest broadcast groups as well as smaller local operations.

McNamara is president of Applied Wireless, Cape Coral, FL.