The GigE Responder provides loopback functionality in a low-cost, palm-sized platform that is the perfect companion to the SunSet MTT Ethernet and Gigabit Ethernet modules as well as the STT Ethernet, STT Metro, STT ONE modules and SunLite GigE unit. When Ethernet and IP traffic passes through a switch or router, the source and destination addresses are checked, logged, and used for directing the traffic. A simple hard loop like those used for TDM networks are insufficient for testing. Instead, a smart loop device must swap the source and destination addresses in the MAC and IP headers.

With a standard, full-featured test set on one end of a circuit and the GigE Responder on the other, a technician can verify throughput, bit error rate, roundtrip delay, packet jitter (delay variation), and quality of service. The Ping and Traceroute function verifies Layer 3 connectivity for Internet access, Voice over IP (VoIP), IPTV, and other IP services.