A connection is established in a communications network responsive to receiving a Dual Tone Multi-Frequency (DTMF) signal at a port having an assigned sequence associated therewith. A dialed sequence corresponding to the received DTMF signal is identified. If the dialed sequence is associated with a request for a specified service, first and second fields of a packet-switched signaling protocol message are populated with the assigned sequence associated with the port. The populated packet-switched signaling protocol message is transmitted over a packet-switched network to request the specified service, and a connection is established to provide the specified service through the port. Related systems and devices are also discussed.