Ethernet over Coax (EoC) Shootout

Published Jul 16, 2015 04:00 AM

Reusing existing coax for IP cameras can cut installation costs dramatically. However, there are endless numbers of Ethernet over coax adapters available, all with differing price points and feature sets, so choosing the right ones can be daunting.

To find out what works best in EoC applications, we bought five models of popular Ethernet over coax adapters, including:

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Testing each in these key areas:

  • Maximum transmission distance: Does each meet or exceed manufacturer specs?
  • PoE performance: Were there any problems powering cameras?
  • Ease of use and advanced features: Were the units plug and play and did they offer bells and whistles?

Key Findings

This chart sums up the comparitive performance of tested EoC adapters in key areas:

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Note: the EnConn Mini-Power's throughput could not be tested like other cameras (see our tests below), but operated only in 10 Mb/s mode at 1000'.

Recommendations

All EoC adapters tested were able to connect and stream a single camera reliably at up to ~1,000' using RG-59, longer than the vast majority of analog camera runs they would replace. Additionally, all units (besides EnConn) were able to achieve speeds over 50 Mb/s (up to 85 Mb/s) at these ranges, more than enough for a single or even multiple cameras.

Because of these factors, the main considerations in most EoC updgrades become price and required featureset:

  • Low cost: If cost if the main issue and low voltage power supply cabling is in place, the EoC Box is by far the lowest cost option, with solid performance up to ~2,000' (specified for 3x this distance). If power cabling can't be used, the Altronix eBridge Plus provides PoE pass through (requiring only coax cabling) at up to 1,500' while still 40%+ less expensive than other options.
  • Maximum PoE range: If cable runs are especially long and users must use PoE up the coax, the NVT EC1700 performed best in our tests, though it is the most expensive of the options tested and requires a dedicated power supply.
  • Advanced features: The Veracity HighWire PowerStar provides some of the highest throughput tested, PoE up the coax via either PoE switch pass through or dedicated power supply, and includes LED status and troubleshooting indicators, providing more link information than all other models tested, though range is shorter than competitors.

Not Recommended

Based on our tests, we do not recommend Veracity's older generation HighWire units, as they have simply been outmoded by the newer PowerStar model, which adds PoE up the coax, PoE pass through, and advanced troubleshooting LEDs at a moderately lower price.

Additionally, while the EnConn Mini-Power was priced second lowest and worked reliably at short ranges, it's limited bandwidth (10 Mb/s instead of 100) and range (1,000' max) make it the most limited of all units tested. Further, it may not be used with non-PoE devices (such as PTZs using low voltage power), and limitation no other adapter had.

Strongly Recommended: Test In Place

Regardless of which adapter is selected, we strongly recommend testing the model in place with the switch/midspan and camera model to be used. Due to variations in cable quality and the potential (albeit limited) for power issues at the far end, this testing may relieve potential unexpected issues.

Price

EoC adapter pricing varies depending on features, with the EoC Box lowest cost at about $70 per pair (not including 12VDC power), though this model does not pass or supply PoE and requires local power at both ends. Units with more advanced features such as Veracity's PowerStar adapters which include status/troubleshooting LEDs or NVT's 4:1 multiple-camera connectivity, are higher in price.

  • Altronix eBridge Plus: ~$200 online, per pair
  • EnConn Mini-Power: ~$100 direct, per pair
  • EoC Box: ~$70 direct, per pair
  • NVT EC1701: $475 online (single camera kit includes two transceivers plus 56V power supply)
  • Veracity HighWire PoE: $400 online, per pair
  • Veracity HighWire PowerStar: $360 online ($180 base unit + $180 camera unit, with optional 57VDC power supply required for max range, $49)

PoE Up The Coax vs. Local Power

Of the five units tested, three support PoE power up the coax, requiring no power supply at the camera end:

  • Altronix eBridge Plus: Supports only 802.3af/at PoE pass through (from switch/midspan) with no option for local power.
  • EnConn Mini-Power: Supports 802.3af/at PoE pass through only. Far end device must support PoE, i.e., cameras, WAPs, but not PCs.
  • NVT EC1701: Supports only local 56VDC power supply, with 802.3af/at output at the far end, no PoE pass through.
  • Veracity HighWire PowerStar: Supports both 802.3af/at pass through as well as a dedicated 57VDC power supply.

Neither the EoC Box nor the older Veracity HighWire support PoE up the coax, requiring low voltage power at both ends of the cable run.

Maximum Range

In order to test functional range, we connected each set of EoC adapters at either end of an RG-59 (20 AWG) coax run, from 500' to 2,000'. We then used this link to connect a camera and VMS to see if the camera could connect and stream (pass) or no link was made (fail).

Only the EoC Box and NVT units functioned at 2,000'. The Altronix eBridge worked without issue up to 1,500', but failed beyond, either dropping significant amounts of packets or simply not connecting. Both Veracity units functioned at up to 1,000', but not beyond.

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Note that while performance varied, no manufacturer overstated their maximum range, listed below. Maximum range specs varied widely, from ~1,100' using Veracity to a whopping ~8,000' using the NVT EC1700E. All specs below use RG-59:

  • Altronix eBridge Plus: ~1,500'/459m
  • EnConn Mini-Power: ~492'/150m (100 Mb/s) or ~820'/250m (10 Mb/s)
  • EoC Box: ~6,500'/2,000m
  • NVT EC1701: 8,000'/~2,500m
  • Veracity HighWire PoE: 1,100'/300m
  • Veracity HighWire PowerStar: 1,100'/300m

PoE Power Issues

While the EoC adapters functioned at the ranged listed above for the majority of cameras, we did encounter occasional issues in testing, where some cameras did not power up at certain ranges or at all. For example:

  • The Axis Q1615 would not power up using any of the PoE adapters which passed through PoE. When plugging the camera in, the link would continuously drop and reconnect every few seconds.
  • Using some integrated IR cameras, similar behavior was seen, though not at all distances nor using all adapters. At short range, cameras typically performed as expected. At 1,000'+, some IR cameras (Hikvision 6162, Avigilon H3A bullet) would cause the EoC adapter to reboot repeatedly when the illuminators turned on, causing the link to fail.

According to manufacturers we spoke to, this is likely due to improper or malfunctioning PoE circuitry requesting more power than is truly available, with no fix other than using local power for the camera.

Because of these issues, we strongly recommend testing your chosen combination of PoE switch/midspan, EoC adapters, and camera on the actual run of coax to be used, as bench testing short lengths may not reveal these issues.

Tested Throughput

Next, we tested the maximum throughput of each unit at distances up to 2,000' (where applicable) using Iperf, a tool which transmits actual packets between two computers to measure throughput, shown here:

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The two Veracity units and Altronix eBridge achieved the fastest speeds in our throughput tests, all 80 Mb/s or higher, while NVT and the EoC Box were lower, ~50/60 Mb/s respectively at short distances, with NVT dropping to ~47 Mb/s at 2,000'.

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Size Comparison

Most of the EoC adapters tested are approximately the same size, about 1.5" x 3". Notably larger is the Altronix eBridge Plus, about a 3.5" square, while the base unit of the EnConn Mini-Power is smallest, only about 1.5" square. The adapters are shown side by side in this image:

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Adapter Features

The Altronix eBridge Plus, EnConn Mini-Power, EoC Box, and Veracity HighWire PoE included no advanced features, simply converting Ethernet to coax and back with basic status lights, if anything.

However, the NVT NV-EC1701 and HighWire PowerStar both include features not found in other adapters

NVT NV-EC1701

The NV-EC1701 includes the ability to connect up to 4 transceiver to a single base unit, i.e, four cameras to one receiver. This is accomplished using a 4:1 BNC splitter, sold individually or as part of a 16 channel rack mount (below). Other adapters are 1:1 only.

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Veracity HighWire PowerStar

The HighWire PowerStar includes status and troubleshooting LEDs not found on any of the other adapters tested. These LEDs show link status for the coax connection, Ethernet status at both base and camera end, and maximum PoE wattage available at the far end.

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In addition to these LEDs, the PowerStar offers the most flexible options for power in our tests, either passing 802.3af/at PoE from a midspan or switch or powered locally via 44-57VDC at either one or both ends. Others supported local power or PoE pass through, not both.

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