The enhanced PacketExpert isa Quad Port Ethernet/IP Tester announced by GL Communications. It now supports RFC 6349 frame work for TCP Throughput Testing Methodology referred to as ExpertTCP. Jagdish Vadalia, a Senior Manager for product development of the company said, “GL's PacketExpert, both PacketExpert 1G and PacketExpert 10G have been enhanced to support RFC 6349 based TCP Throughput (ExpertTCP) test functionality.
PacketExpert 1G has four 10/100/1000 Mbps Electrical/Optical ports and PacketExpert 10G has two 10Gbps Optical ports and two 10/100/1000 Mbps Electrical/Optical ports and both are capable of Bit Error Rate Testing (BERT), Smart Loopback, RFC 2544 Testing, Record and Playback, Single Stream and Multi-stream Simulation of IP Links and Impairments (IPLinkSim and IPNetSim), Multi-Stream Traffic Generation and Analysis, PacketBroker, and Y.1564 Testing (ExpertSAM).
IP Network operators and Service providers need to verify that their networks are performing well and meet the Service Level Agreements (SLA) with the customers.
To verify Ethernet/IP based networks, current widely used standards are RFC 2544 or Y.1564. However, both these standards are meant for testing at Layer2 or Layer3 (Ethernet or IP layers). Though these tests are necessary, they are not sufficient, because they do not cover testing at TCP layer.
Most web-based applications like Http, FTP, E-mail etc. run over TCP. Even many modern web applications like Facebook, YouTube and the like use TCP. Even if service provider networks are tested using RFC 2544 or Y.1564, customers may still face problems with TCP throughput.
Says Vadelia, “The TCP throughput may not match the throughput at the Ethernet/IP layer. This is because TCP throughput depends on factors like the end node TCP Window Size, buffer size of intermediate network nodes etc. Also, impairments like latency and packet drops causes TCP retransmissions, severely affecting the TCP throughput. So, there is a gap in the current testing methods and to cover the gap RFC 6349 frame work has been devised.”
Vadalia further explained, “ExpertTCP performs bidirectional TCP throughput measurements in combination with another unit at the remote location (other end of the network), that acts as the TCP server. Many real-world networks are not symmetrical. There may be significant differences between upstream and downstream directions.” He added, “ExpertTCP supports both Upstream (Client → Server) and Downstream (Server → Client) direction testing. Bidirectional simultaneous testing/unidirectional testing can be done. Results are reported for both directions.”