IEEE 802.3ah 2Base-TL

The IEEE802.3ahworking group has defined two interfaces for Ethernet in the First Mile( EFM): 10Pass- TS for high data rates and short distances and 2Base- TL for lower data rates and longer distances. The latter is used for midband Ethernet. 2Base-TL supports Ethernet point-to-point connections over a voice-grade cable( VG).

At least 2 Mbit/s can be transmitted over 2.7 km via the 2Base-TL interface using G.SHDSL full duplex. The theoretically possible data rate is 5.69 Mbit/s for a copper twisted pair. The physical layer optionally supports aggregation and bundling of multiple copper twisted pairs. Bundling multiple twisted pairs results in an increase in the data rate. In practice, seven to eight twisted pairs can be bundled.

For 2Base-TL, the data rate can vary depending on the cable length, gauge value, and number of bundled cables.

As can be seen from the interface designation, it operates in the baseband (base) and cannot be used on lines on which telephony via POTS is taking place at the same time. However, it can be used for all Ethernet services such as Internet telephony( VoIP).