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By modernizing traditional methods of outside plant augmentation, 
Comtest reduces cost up to 70% and improves high speed internet performance and stability up to 50%.

Comtest innovates where no one else does

Our EMI solutions provide superior stability and improve customer experience by increasing speed, reducing strains, and eliminating intermittent issues.


Secondary protection design adds stability—better protection and self-recovery after service disruption events mean a better customer experience overall.

Discover the benefits of secondary protection →


20+ dB reduction in Near End Cross Talk (NEXT) across the spectrum.

See real crosstalk reduction results →

Data rates

Comtest line conditioners increase data rates, giving our customers a huge advantage in the service performance race.

Learn how Comtest increases your profitability →

Superior protection against transient events

Comtest solutions provide faster response time to impulse events (lightning, transient power, etc.) than gas discharge tube (GDT).

Faster response time results in better protection of the equipment.

Protection resets after the event has passed and the customer is back in service.

Figure 1 demonstrates the ability of the protection to reset and put the customer back in service after the event has passed. Circuits with the solid-state respond to impulse (lightning) and transient power events much quicker than those with GDT alone.

Figure 1: Voltage on the circuit with GDT and sidactor protection - with applied impulse voltage of 1000 V/μs
Secondary protection improves customer experience

Better protection and self-recovery directly correlate to reduced repair calls from customers, field dispatches to repair or replace CPE, and a better customer experience overall.

Improved xDSL crosstalk

xDSL crosstalk impacts service in both high and low density situations; impact is measured after as little as three lines.

Comtest solutions are 6x quieter than conventional methods used today, with 20+ dB reduction in NEXT.

Figure 2 illustrates reduced crosstalk on lines using Comtest components compared to lines using a traditional terminal block.

Figure 2: Crosstalk Telecommunication Terminal Block vs Comtest SA-2811-0001
Crosstalk reduction results in higher customer satisfaction

Reduced xDSL crosstalk translates to improved stability, reduced errors, higher margin potential, and higher sync rate potential.

Improved stability and downstream rate

Comtest components reduce errors and improve downstream data rates.

Real-world improvements mean lower operating expenses and service reliability.

Figure 3 shows downstream (DS) code violations and Figure 4 shows the DS minimum error free transfer rate (EFTR); both measured over 30 days. A Comtest line conditioner was placed in the network interface device (NID) March 19th, after which the elimination of DS code violations is observed in Figure 3 and a significant increase in the DS EFTR is observed in Figure 4.

Table 1 summarizes relevant results inferred from the collected data.

downstream code violations
Figure 3: DS code violations
downstream minimum error free transfer rate
Figure 4: DS minimum EFTR
Before Comtest EMI After Comtest EMI
Collection date 2019-03-18 17:31:52 2019-04-01 12:02:32
Stability Stable Very stable
Downstream rate (kbps) 44942 56349
Upstream rate (kbps) 7167 7167
Running standard G_993_2_Annex_A_998_8B_D32_EU32 G_993_2_Annex_A_998_8B_D32_EU32
Estimated loop length (m) 674 677

Table 1: Summary of DS performance results collected before and after application of Comtest EMI-reducing line conditioner March 19, 2019.