Tech Trends: Ethernet Cabling Alternatives
In past issues, I have written about the usefulness of Cat 5e+ cabling alternatives – usually coax – to take advantage of existing cabling infrastructure in lieu of running new Cat-rated cable. Traditional suppliers of the conversion devices include companies such as NVT Phybridge and Veracity, and established companies such as Altronix, have entered the fray.
These conversion devices, which are normally bought in a set, usually convert the data signal to a higher frequency (in the case of fiber optics, frequencies in the infrared range), modulate, and then perform the reverse process in a (hopefully) transparent manner. The economics can be compelling when it comes to both cabling costs and installation time.
With the advent of PoE and suppliers’ own product developments, product line extensions have proliferated. For example, Altronix, with its roots in traditional power supplies, now offers products such as Ethernet/power over coax, multi-port mid-span injectors, hybrid fiber-copper Ethernet switches, and units configurable to provide 60 W of high PoE power.
Ethernet range extenders can be powered by mid-span injectors and increase the Ethernet range five-fold over single or two twisted pair cable.
Increasingly, the market is seeing an expansion of switch products – both unmanaged and managed – that provide built-in ports with something other than standard RJ-45 physical interfaces for local (non-uplink) ports.
Recently, I had the chance to visit NVT Phybridge to learn more about its managed “Long Reach” switch products. Phybridge launched in 2006 to focus on the VoIP area, and the company acquired NVT in 2015 to expand its footprint in security.
As telephony began its analog-to-digital VoIP migration, it created a cabling scenario not unlike security when it began its own transition to IP. Miles of installed two-conductor UTP cable, terminated in RJ11 blocks, were on the threshold of obsolescence and replacement with network cabling.
Phybridge products were conceived and designed to provide two-wire interfaces built into the Ethernet switch to directly connect to the existing cable infrastructure. The product worked well enough to prompt Cisco to assign parts numbers to it – I suspect because it helped speed the migration to VoIP and boosted the sales of IP telephones.
Today’s managed version, the POLRE (Power over Long Reach Ethernet) series provides 24 or 48 ports of PoE over a single pair reliably up to 1,200 feet. The product line has also expanded to include long-reach switches (FLEX series) for two-pair Cat-rated UTP, where, up to standard 100 m Ethernet distances, no far-end conversion is needed. With a far-end converter, up to 2,000 feet of PoE+ power is achievable, in addition to 100 m from the converter to the end-point. The CLEER series provides similar distances over coaxial cable.
I was initially working under the assumption that packaging the cabling interfaces into the switch was only to provide a neater, cleaner interface at the demarcation point between the conventional network and long reach equipment. I had been more impressed by the managed switch’s GUI which was clear, user friendly, and instructive in the information displayed. For example, a dynamic bar graph for each port shows a display of current power consumed. For me, these and similar products from other manufacturers looked like (and still are) ideal candidates for retrofit applications.
What I have since learned is that this integral cabling-switch technology has its place in new installations also, particularly with Cat-rated cabling. With conventional technology, edge switches must be within 328 feet of the connected endpoints. The Long Reach technology potentially allows fewer switch locations (and switches) to be provisioned because the reach can now extend to more than 2,000 feet.
The reduction in switch locations also brings a reduction in the supporting physical, electrical, power and security infrastructure. That translates to fewer equipment rooms and closets, UPS units, door controls, racks, patch panels, etc.
Further valuable space may be allocated for other purposes. Phybridge points to an installation at Kansai International Airport in Japan, where FLEX switches were used to connect and power more than 250 Xovis person tracking sensors, reducing the number of IDF closets by 90 percent.
Having this flexibility may lead to changes in another aspect of network topology. While the arguments about converged networks may be beginning to fade, configuring physical security networks with these switches provides a way of provisioning security and other IoT devices on their own infrastructure, including power monitoring and appropriate backup power. A limited number (perhaps as few as one) of connections would tie the security network to an enterprise network, providing an expedient means of separating the two if needed.
The advantages discussed here are not unique to security but apply also to any Operational Technology (OT) network where distances vary greatly and PoE requirements are common. OT is defined by Wikipedia as “the hardware and software dedicated to detecting or causing changes in physical processes through direct monitoring and/or control of physical devices.” It is differentiated from IT by its purpose and tendency to have unique requirements.
A word of caution with any PoE switch – be sure to understand the probable power consumption of your loads relative to the total power capability of the PoE Switch.
Just because an 8-port switch can provide 30W PoE+ power from each port, that switch might not necessarily be rated for 240W (required if each port was used to the max).
Also, be mindful of the standby power requirements. If switches are provisioned by IT, they may not fully understand the time requirements for security devices to function in the absence of primary power.
Ray Coulombe is Founder and Managing Director of SecuritySpecifiers and the CONSULT Technical Security Symposium. Contact him at [email protected], through LinkedIn at www.linkedin.com/in/raycoulombe or follow him on Twitter, @RayCoulombe.
