local area network (Photo credit: benschke)

Transparent LAN Service (TLS) is an Ethernet service that allows a business customer to connect together multiple Local Area Networks (LANs) without complex protocol conversions, carrier equipment or expensive dedicated facilities. Probably the best way to think of it functionally is as the Ethernet version of frame relay, only much improved in terms of speed and cost. The product goes by many different names, but we prefer to call it Transparent LAN Service because transparency is the major benefit it brings to businesses. Properly configured it removes all of the barriers that were in older technologies and connects LANs and WANs seamlessly.

Transparent LAN service can be configured in multiple configurations including both point-to-point or multipoint-to-multipoint arrangements. In the past businesses with multiple locations had to buy dedicated facilities to connect their LANs together. And typically the dedicated facilities were expensive, were slower than the speeds of the corporate LANs and had issues like carrier demarcation points and protocols to deal, which required quite a bit of expertise on the part of the business IT personnel.

Businesses with multiple locations like banks and grocery stores, educational institutions and government agencies are examples of institutions that want simple, distributed LAN connectivity. These kinds of business customers have outgrown the traditional LAN connectivity offered by most telcos because they have significantly greater bandwidth needs than in the past because of applications like remote monitoring, distance learning, business location integration, business disaster recovery and interconnection to cloud services.

There several variations of the service with the two most common being:

Any-to-Any service (E-LAN). This service allows any connected site to talk to any other connected site across the carrier’s network, with only one physical connection at each site. With this service, the customer controls VLAN IDs so that he can segment traffic in any desired manner among his connected LAN locations. All sites share one EVC (Ethernet Virtual Circuit). To the customer, this service is “transparent” across the carrier’s network and the customer controls everything.

Point-to-Point (E-LINE). This is a point-to-point EVC (Ethernet Virtual Circuit) solution where the carrier controls which customer sites can talk to which customer sites. This service allows one or more EVC per User Network Interface (UNI). The customer does not control VLAN IDs so that he can’t segment traffic among his locations. With the carrier controlling the site ingress and egress, better Quality of Service can be offered across the carrier network. To the customer, this service is not as “transparent” across the carrier’s network, but many customers prefer that the carrier control the network.

There are a number of benefits to customers from Transparent LAN Service

• Reduces IT personnel expertise requirements for WAN hardware, software, protocols, testing and maintenance;
• Reduces WAN equipment requirements;
• Reduces complexity of networking – single network capability;
• Can increase WAN speed to LAN or near-LAN speeds;
• Increases network manageability – can look like single LAN for all customer sites;
• Scalable bandwidth that can be changed as needed;
• Accommodates a single physical interface at each customer site;
• Scalable site connectivity – easy to add or remove sites from network;
• IT staff can still self-manage network if desired;
• Allows efficient redundancy across carrier’s network;
• Allows QOS access carrier network.

And there are benefits to the carrier from offering Transparent LAN Service

• Can leverage fiber and IP network as well as legacy transport network;
• Managed services make your customers more dependent on your network and value-added services;
• Less costly network compared to SONET;
• Multiple services can be provided over a single network;
• Can offer value added services like QOS/Performance Control over delivery of customer’s traffic.

Transparent LAN Service can be a valuable addition to your carrier Ethernet service offering. This product can support multiple locations for the same customer and can bring solutions for greater bandwidth to WANs, video content delivery, disaster recovery, and cloud services. When done right this is a killer app for larger businesses.

While this product sounds simple there are a lot of options and it can be tricky to set up. You can call Derrel Duplechin of CCG at (337) 654-7490 if you want to know more about the product.