This table is a guide only to modem speeds that can be expected depending on the distance you are from the exchange and the Signal to Noise Ratio (SNR) of the telephone service ie. the further you are away from the telephone exchange, the slower your modem connection speed.
 

Typical Performance of 2 wire V.34 Series Modems for Composite Access range cable (0.4mm) + 1 PCM channel
 

Modem Speeds (bits/sec)	Signal to Noise Ratio (SNR)	Distance to Exchange (km)
2400	9	11
4800	11	11
7200	13	11
9600	15	10
12000	18	10
14400	21	10
16800	24	10
19200	26	10
21600	28	9
24000	31	7.5
26400	35	5.5
28800	36	4.3
31200	38	3.2
33600	40	1.1

Source: Telstra Modem Performance Tables, Service Engineering

Notes
1. This table is a guide only & is not representative of a specific model modem.  It is an at attemp to provide a quantitative  estimate of a range of modem types tested in a particular V series classification.

2. Access Line Range is the sum of the Customer Access Network (copper cable) for the "A" and "B" end of the End to End service that the modem can handle without any impairments introduced.

3. Composite Access Range is the typical amount of copper based Customer Access network that the modem can tolerate in conjunction with at least one digital Pulse Code Modulation (PCM) channel & a moderate noise level.

4. V.34 modem performance estimates relate to a -15 dbm transmit level and a -67 dbm noise floor.