data are limited to 19.2 or 21.6Kbps connections. Long cable runs are also reasons for connect rates at 26.4K or below. 26.4Kbps, perhaps with occasional 24K and 28.8K (ITU v.34 protocol) Usually indicates a SLC that has what is called a "universal" interface to the Telco switch. Such an interface adds an extra DA/AD conversion, which prohibits a V.90/92 connection, and also adds at least 3 dB of quantization noise and
