Switched local access to a network requires a call setup process, such as that found with POTS/PSTN or ISDN-BRI/PRI service. Access to the service provider's network is dependent on the
The customer can access a NSP's LD network in one of two ways, using either a Prescribed Interchange Carrier (PIC) or Carrier Identification Code (CIC). The PIC code is the IXC the customer/end-user designates to carry all 1+10-digit long-distance calls. The CIC is used when the customer/end-user wants to tell the LEC which carrier to use for 1+ service, either via presubscription or casual dialing. Casual dialing is when the customer/end-user dials the 7-digit CIC prior to the 1+10-digit dialed number, such as dialing 10-10-228-1-703-555-1212.
Appendix A "PIC Codes," lists the PIC/CIC codes available for use as of 6/1/2002.
Local access circuits have two termination points: the customer
Light Termination Equipment (LTE)
- Fiber-optic transmissions terminate here, often in the form of fiber or lightwave multiplexers (muxes). LTE can be used to terminate fiber-optic signals from a customer site or for interconnection of fiber-
Multiplexer DS1/DS3 (M13), pronounced "M-One-Three"
- Performs both multiplexing and
Digital Cross Connect System (DACS or [DXC])
Switch - This could be a voice or data (ATM or Frame Relay) switch. The switch is an interface to the respective network for which it provides service, such as voice or data.
Customer site access to network services (from a NSP) requires a physical connection, often in the form of
There are two types of access circuits:
Dedicated - DS0, DS1/DS3, OC-x
Switched - POTS/PSTN, ISDN-BRI/PRI
Dedicated access circuits provide permanent connectivity to a network service provider, whereas switched access circuits provide on-demand connectivity. Switched access requires a call-setup procedure, often in the form of dialing a PIC/CIC from the
CSU/DSU or other signal termination device (for example, WAN interface card (WIC) in a Cisco Series Router
(Extended) Demarc point
Punch-down block (also known as 66-block)
Local Loop (Copper or Fiber)
LEC/IXC trunk between the LEC CO and the IXC CO (depending on the subscribed service; for example, long-distance voice or data service)
The following components are fundamental to a LEC/IXC CO:
LTE - Light termination equipment
M13 - Multiplexer DS1/DS3
DACS (or DXC)
Voice or data switch