Network Test Equipment from GL Communications, Inc.

T3/E3 Analyzer -- UT301/UT302

T3/E3 Analyzer -- UT301/UT302 -- View Larger Image
T3/E3 Analyzer -- UT301/UT302-Image

A T3 line is an ultra-high-speed signal capable of transmitting data at rates up to 44.736 Mbps. An E3 signal is situated at the third level within the Plesiochronous Digital Hierarchy (PDH) and has a bit rate of 34.368 Mbps.
T3 or E3 has two flavours channelized (structured) and unchannelized (unstructured).

  • In Channelized (Structured), a T3 (DS3) consists of 7 T2s (DS2) and each T2 consists of 4 T1s (DS1), thus a total of 28 T1s, or 672 full duplex voice channels are provided. Similarly, an E3 consists of 4 E2s and each E2 consists of 4 E1s, thus a total of 16 E1s, or 480 full duplex voice channels are provided. Thus, a channelized T3 signal carries 28 T1 signals, each operating at a rate of 1.544 Mbps. A channelized E3 signal carries 16 E1 signals each operating at a rate of 2.048 Mbps.
  • In Unchannelized (Unstructured), T2s or T1s or E2s or E1s DO NOT exist within T3 or E3. Instead, most of the capacity within 44.736 Mbps for T3 and 34.368 Mbps for E3 is used for data, with a small amount for overhead. With the advent of the internet, T3 (DS3) and E3 can be used to transport not only data, but also packetized voice, and packetized video. Example protocols include Asynchronous Transfer Mode (ATM), PPP, HDLC, and Frame Relay.

GL’s T3 E3 Analyzer is available as portable as well as a rackmount system. A portable USB-based unit supports 2x T3 E3 ports per unit. A 2U Rack supports 6x T3 E3 ports (6 * 672 DS0s) per unit. Multiple rack units can be stacked together for greater scalability.

The T3 E3 Analysis software compliments the hardware and supports simultaneously monitoring up to 12 x T3 E3 lines (2x Rack units or 6x Portable units) for all alarms, frame errors, signalling and data. If one adds the Channelized T1 Analyzer software to the system, then the T1s within the T3s can also be analysed in software, 12 x T3 E3 lines (=12*28 T1s) constituting 336 full duplex T1s, or 672 simplex T1s monitored simultaneously using a single Rack unit. With additional applications, such as record-only, one can also record traffic at DS0 levels.

GL’s T3 E3 Analyzer is capable of processing signalling, voice, and data full T3 (DS3) or E3 data streams, dropping and inserting T1 (DS1) or E1, and analysis of HDLC, ATM, Frame Relay, and PPP Protocols. It includes various signal testing capabilities for Unchannelized (Unstructured) and Channelized (Structured) T3 E3 Traffic.

The channelized option in the T3 E3 Analyzer uses “software-only” approach to support direct access to all 2x28 T1s or 2x21 E1s or 2x16 E1s on a T3/E3 line per board for analysis and monitoring– all within a single PC, including differing T1/E1 framing formats, physical layer alarms, and payloads.

GL's T3 E3 Analyzer also includes scrambling and subrate features. Subrate allows fractional bandwidth, i.e. less than the full 44.736 Mbps. Scrambling improves synchronization performance by randomizing repetitive patterns and long strings of zeros.

  • Analysis/Emulation of T3 (44.736 Mbps) and E3 (34.368 Mbps)
  • Analysis/Emulation of ATM, PPP, HDLC, and Frame Relay signalling
  • Record / Playback of entire T3 or E3
  • Monitoring & generating alarms, and error insertion
  • Analysis of all 28 T1s (1.544 Mbps each) per T3 port, or 16 E1s (2.048 Mbps each) per E3 port in Channelized mode
  • Analysis of Fractional T1s and E1s, N x T1s or N x E1s
  • Analysis of any combination of DS0s (64 kbps each) within the T1s or E1s ( for example, each T3 port has 28 x 24 = 670 DS0s for T1 or 21 x 32 = 672 DS0s for E1)


Product Category
Network Test Equipment
Equipment Type
Protocol Analyzer
Network Protocol
T3, E3