This read-only value reports the initial connection speed, in bits per second, that was negotiated when this modem session first established. Admins compare this baseline rate against the current cmmRxRate and cmmTxRate to detect whether the connection has degraded, or retrained to a slower rate, since it started. For example, a session whose cmmInitialConnectRate was 33,600 bps but whose current cmmRxRate has dropped much lower would indicate significant line-quality degradation partway through the call.