The ZyXEL transceiver family follows industry standards to assure compatibility with switches from other manufacturers without barrier set by proprietary technologies. With ZyXEL's comprehensive Fast, Gigabit and 10 Gigabit transceiver product range, also Direct Attached Cable 1 M/3 M, users can just plug the proper model onto the network to extend the physical coverage. Independent transceiver design provides the highest network maintenance flexibility. Transceivers can be freely added when required, and infrastructure upgrades or transceiver repairs can be done easily by just replacing the transceiver instead of the whole device. Traditional fiber optic networking requires two strands of fiber to accomplish communications, in which one strand is reserved for sending signals, while the other is for receiving. On the other hand, bi-directional, dual-wavelength transceivers can establish communications over just one strand of fiber by using two separate optical wavelengths: one receives and the other transmits signals. Transmission capacity can be expanded immediately without additional cost laying new fiber. The enhanced digital interface enables a real time link to be established between the switch and the SFP transceiver. This enables the switch to access operating parameters within the fiber link. This includes digital features such as soft control and monitoring of SFP I/O signals. In addition, the DDMI functionality enables the capability to implement digital alarms and warnings. This feature ensures that the business can be proactive in preventative maintenance of the network and ensure business continuity.