TDMoIP
TDM-over-IP (TDMoIP) is a technology that enables voice and leased-line services such as video and data to be offered inexpensively over packet networks while retaining the reliability and quality of the public switched telephone network (PSTN). TDMoIP is commonly known as a pseudowire emulation technology that extends voice or data circuits. The emulation is transparent and yields the lowest cost per managed bit. TDMoIP pseudowire typically emulates T1/E1 or T3/E3 circuits.
Conventional TDM networks are highly deterministic with a source device
transmitting one or more octets to a destination device. This occurs by
a dedicating-bandwidth channel every 125 μs. As a circuit is connected
the delay through a TDM network is predictably low. TDM delivers timing
with the data while tightly controlling jitter and wander.
Timing is delivered along with the data, and the permitted variability (jitter and wander) of TDM clocks is tightly defined. In addition, the infrastructure supports a rich set of user features via a vast set of signaling protocols.
Thus, TDM is not natively design for packet switch networks. Even though packet based networks are more efficient than TDM networks, they share bandwidth causing it to be inherently non-deterministic. Packets entering the network must compete for bandwidth leading to packet delay variations and lost packets. The asynchronous nature of packet movement throughout the network insures that packets will not necessarily arrive at regular intervals, evenly spaced or even in the same order of transmission.
Packet-switched networks (PSNs), such as IP/multi-protocol label switching (MPLS) systems, are more efficient than TDM networks due to bandwidth sharing. However, this sharing leads to PSNs being inherently non-deterministic.
To solve these problems, TDMoIP emulates TDM transmission (T1, E1, T3, E3, and N*64K links) by adapting and encapsulating the TDM traffic at the network ingress. The adaptation denotes mechanisms or packet manipulation that adds packet or framing information on the payload to enable its proper restoration at the egress. This framing allows for the TDM signaling and timing to be recovered and limit the amount of packet loss. More importantly, this approach allows for seamless integration in existing public networks.
Currently Luxcore is focusing upon two technologies:
