ADTRAN T1-FT1 user manual Fractional T1

Chapter 1. Introduction

performance of their service offering. Since the introduction of ESF, equipment that is installed in private networks can also provide the same performance information to the user.

Fractional T1

Fractional T1 lets the buyer purchase less than a full T1 circuit between two points. Most carriers offer fractional T1 in increments of 56 or 64 kbps. Connection is made to the same network elements. The network allows multiple users to share the same interoffice T1 bandwidth.

Fractional T1 remains almost exclusively an Inter-Exchange Carrier (IXC) service. Local Exchange Carriers (LECs) typically do not offer FT1, so the user's proximity to the IXC's point of presence (POP) is key in the savings that fractional T1 offers.

Fractional T1 local access is available in two forms, 56kbps or a full T1 line. In 56 kbps the required number of DDS lines is extended from the IXC POP and the bandwidth is combined at the office on an outbound T1 circuit. The user pays for the individual 56K lines and the amount of the interoffice T1 utilized. In T1 access, the user pays for a full T1 to the IXC POP and then only for the bandwidth utilized.

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