Chapter 6. Local Access

This chapter covers the following topics:

• Dedicated Local Access Configuration

• Switched Local Access Configuration

• Local Exchange Carrier (LEC) Central Office (CO) Configuration

Access to a network service provider's (NSP) services requires a physical connection (landline or wireless) to that NSP's office. This physical connection between the customer site and the NSP office is known as the network local access. This local access, also known as the local loop or the last mile, supports both dedicated and switched services.

NOTE

A landline is a cable that is attached to the ground between two end-points for example, a telephone line between telephone poles. Landlines can be suspended, as is the case with telephone poles, or they can be (and often are) buried underground.

Dedicated access is a permanent connection terminating (from the customer's perspective) at either the local exchange carrier's (LEC) or Interexchange Carrier's (IXC) central office (CO). Examples of dedicated access circuits are DS0, DS1/DS3, or OC-x. Switched access is not a permanent connection, requiring the customer/end-user to initiate a call setup process. Examples of switched access are POTS/PSTN or ISDN-BRI/PRI service.

NOTE

Plain old telephone service (POTS) the telephone system we know and use today. POTS runs across the public switched telephone network (PSTN).

Integrated services digital network (ISDN), an international communications standard for sending voice, video, and data over digital telephone lines or normal telephone wires. ISDN is available in two offerings: Basic Rate Interface (BRI) at 144 Kbps (2B + D) and PRI at 1536 Kbps (23B + D). The B(earer) channels are 64 Kbps and carry the signal (voice/data), and the D(ata) channel carries the signaling: 16 Kbps for BRI, and 64 Kbps for PRI.