This Recommendation specifies portions of clause 61 of [IEEE 802.3ah]-2004 amendment to carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specification as a normative reference and identifies the requirements for multi-pair bonding in [IEEE 802.3ah]-2004 that are different in the United States. Further, this Recommendation specifies the requirements for extending the bonding methods in [IEEE 802.3ah]-2004 to xDSL technologies other than very high-speed digital subscriber line (VDSL) and single-pair high-bit-rate digital subscriber line (SHDSL).

This Recommendation has the following four objectives:

1) provide support for operation of xDSL technologies on multiple pairs of voice-grade twisted pair cable;

2) provide 100 Mbit/s burst data rate at the Ethernet media independent interface using rate matching;

3) provide full duplex operation;

4) provide a communication channel with a mean bit error rate (BER) at the α/β service interface of less than 10⁻⁷.