ISP Terminology & Lexicon - Full Span Solutions


ISP Terminology & Lexicon

The Internet Service Provider (ISP) world is full of terminology, acronyms, specific products and technology that it’s often difficult to know unless you work with it on a daily basis.  The aim of our lexicon is to cover as much of this as possible. 

Data Circuit Types

There are several types of data circuits available to connect your business to the internet, other branch locations, or your business partners.  Below we list some of the most common options as well as a few details on why that particular circuit could be a fit for your connectivity needs.

Business Broadband:

Business Broadband is more analogous to your home internet service.  Its often delivered over a similar medium as consumer services such as coax, shared fiber access, or fixed wireless.  Broadband is low cost but can offer high bandwidths.  There are typically few to no service level guarantees on broadband service, unlike DIA service.

Dark Fiber:

Some service providers will sell access to individual strands of fiber between two different points.  These services have no electronics involved and are simply a dark fiber lease.  Leases are often 5, 7, or 10 years. 

An Indefensible Right to Use (IRU) agreement is similar but functions as a granting of ownership of part of a cable for a period of time.  Typically 10 years or more.

Dedicated Internet Access:

Dedicated Internet Access (DIA) is a service that offers a fully committed data rate with no over-subscription of the bandwidth like broadband. A DIA connection will also have a Service Level Agreement (SLA) that guarantees the service level of the service. 

Ethernet Private Line

An Ethernet Private Line, or EPL, is a point-to-point layer 2 Ethernet circuit.  These are designed to connect to key business locations with a dedicated service while offering more path protection of a wavelength.  An EPL is also more flexible and does not need to be a full line-rate service.  Most EPL services can support jumbo frames but it is important to confirm with the service provider before ordering.

Ethernet Virtual Private Line

An Ethernet Virtual Private Line or EVPL is a virtual circuit delivered between two sites.  The remote site will connect back to a single port shared between other EVPL circuits.  This design allows a customer to rapidly deploy new sites without the need for additional hardware, cross-connects, etc at the hub site.  Be sure to understand the differences between an EPL and EVPL if considering connections between your business locations! 


A wavelength circuit is a full line rate Layer 1 service to connect two key locations with a fixed path, low latency connection.  A wavelength service will take in a customer connection on each end and then shift the light colors over the fiber to transmit between sites.  Several customers may ride the same fiber pairs as a wavelength service is typically multiplexed with other wavelengths of light on the same circuit. 

As wavelength service can also be “protected” meaning that two physically diverse paths can be implemented to give the customer redundancy in case of a fiber cut or equipment failure.   A protected service will typically be more expensive.  Because a wavelength takes a fixed physical path a KMZ file can often be generated showing the full path of the route for the customer’s peace of mind as well.

Data Circuit Terminology:

There is a lot of technical and industry terminology around data circuits.  This list isn’t conclusive but aims to cover the most common terms.

Type I:

Type I circuits are owned, supported, and billed all by the same service provider. 

Type II:

A Circuit is a “Type II” when the network access or the last mile connectivity is provided by a service provider who is different than the provider who provides the service itself. 

As an example, let’s say you buy a point-to-point connection from Windstream.  The HQ address has Windstream fiber but the remote site only has Comcast available.  The service is a Windstream service but the physical infrastructure into the remote site is a Type II Circuit from Comcast.  The Type II provider will sell the connection to the provider wholesale and then that provider offers you the complete solution.


A reseller is a service provider who buys a Type I Circuit at a wholesale rate and then rebrands it as their own selling it to an end customer.  In very rare instances, we hear this referred to as “Type III”.  There are a number of reasons this might be a benefit from working with one of our reseller partners:

  • Consolidated Billing – The reseller can sell services from dozens of underlying Type I providers but will them all together for you the end customer.  This saves time (and money) when it comes to processing payments
  • Consolidated Support – Like billing you will have a single phone number for support. 
  • Access to Providers You Didn’t Know Existed – Resellers have a LOT of relationships in the industry.  They have creative ways to solve problems.  They know how to find connectivity just about anywhere even if it’s a niche option.
  • Addons – Some resellers offer additional features that the underlying provider won’t.  Managed routers, a billing portal, included 4G backup, etc are just a few examples.
  • Pricing – A reseller has a lot of leverage with a Tyle I provider if they are spending hundreds of thousands of dollars with them each month.  This keeps resellers competitive with the Type I provider’s direct sales team. 


An aggregator is a provider who can bring multiple providers together into a single solution.  For instance, if a customer would like to deploy an ELAN service to 10 sites but there is no single service provider who can reach them all the sites would need to be “aggregated”.  Essentially an aggregator can buy a Type II access circuit from a local provider at each location.  These circuits are then taken back to that aggregator’s core network and connected together to build an enterprise solution.  The Aggregator then installs, bills, and supports that customer for the life cycle of the entire solution.