PRI over Cable Cost Savings

Many businesses use ISDN PRI trunking to provide phone service for their organizations. The original motivation to move from analog business lines to PRI was the cost savings that T1 technology offered. Now there is a newer and even better cost option called PRI over Cable.

Regardless of the delivery technology, ISDN PRI is a well-established standard for bundling up to 23 business telephone lines on a single digital cable. Why 23? It’s because T1 lines were designed to have 24 channels, each capable of transporting one high quality digitized telephone conversation. One channel is reserved for signaling and Caller ID, leaving 23 channels available for phone calls. Each channel is equivalent to one analog phone line. By bundling them, you can almost always save money over ordering 23 individual phone line.

What’s more, nearly all modern PBX telephone systems and many key telephone systems support the ISDN PRI standard. There is a PRI jack on the back of the system or a plug-in accessory card. Many larger business phone systems accommodate multiple PRI lines so you can have 46, 69, 92 or more outside phone lines if your company is large enough to need this many.

ISDN was designed around T1 lines, but there is no reason that more modern packet switched networks can’t also provide phone lines to meet the ISDN specification. It’s all a matter of hardware and firmware on circuit cards to get the signals formated properly.

Comcast, the largest cable operator in the US, is now offering PRI telephone trunking over their Hybrid Fiber Cable (HFC) system. If you are only familiar with Comcast as a provider of Cable TV service or broadband, you may be surprised to learn that Comcast is the third largest telephone company in the country. The other possible surprise is that Comcast is a business as well as residential service provider.

Coaxial cable has bandwidth capabilities far beyond those of twisted pair copper telephone wiring. This is especially true when most of the network is built on fiber optic cabling and only the last mile or less uses coax. Coax is cheap, reliable and well-proven technology. There is plenty of room on that coax to delivery television, broadband and telephone services, including ISDN PRI.

But isn’t broadband telephone fraught with performance issues? The Internet often isn’t up to traditional telephone standards when it comes to voice distortion and latency, the annoying time delay that makes you pause during two-way conversations. That’s why Comcast keeps their broadband and telephone signals separate. They’re both riding the same cable, but in different channels so they don’t interfere. TV signals are also on the same cable in their own assigned channels.

What makes PRI over Cable a great option for a small to medium size business? Consider that you can get a 6 channel telephone trunk capable of serving up to 24 employees plus 22/5 Mbps broadband Internet service for less than the cost of many T1 lines. Most companies need both telephone and Internet service, and Comcast’s business class Business Class Trunks and Internet with broadband speed up to 22 Mbps download easily fits the need.

Do you need a larger phone system capacity or are concerned that you will in the future? No problem. Comcast lets you add to your PRI service in single channel increments. Many ISDN PRI services now come with a full 23 lines even if you don’t need that many. Having a system that is scalable for both phone lines and Internet bandwidth gives you the ability to buy just what you need now and be able to easily upgrade in the future.

Could you benefit from the flexibility of business telephone service that will grow with your business or just want to see if you can save on ISDN PRI over Cable with or without bundled broadband service? If so, get pricing and installation times for ISDN PRI and bundled services for Comcast Business Class. There are also attractive voice and data plans from competitive carriers where cable services are not available.

Cable, T1 and EoC

Today, there are three excellent broadband options for the small to medium size business. They cost roughly the same, but offer different options. Which do you choose? Let’s take a closer look at business-class Cable, T1 lines and Ethernet over Copper.

We’ll start with T1 lines because they are the mainstay of SMB connectivity. T1 lines come in several flavors depending on what you want to do with them. They’re all based on the same technology developed by the telephone industry half a century ago.

T1 is a T-carrier technology based on transmitting digital signals over ordinary twisted pair copper wiring. It takes two copper pair to make one T1 line. One pair is used for upload, the other for download. When used for telephony, one pair is talk and the other is listen. The speed of the digital signal on the line is 1.5 Mbps. This doesn’t vary. The equipment at each end of the line is synchronized to maintain a steady bit rate regardless of whether anything is being transmitted or not.

Originally, the purpose of this arrangement was to transmit telephone calls in channels called DS0s. There are 24 channels on a T1 line. You can use them separately or combine all the channels to make one large broadband pipe. The most common T1 telephone line now is called a T1 PRI or ISDN PRI. It has 23 separate phone lines plus one channel for signaling and Caller ID.

A broadband T1 line delivers a fully symmetrical bandwidth of 1.5 Mbps. The upload and download speeds are the same. This line can connect directly between two business locations as a private line or it can be used to connect to the Internet or another network, such as a MPLS cloud network. When used as an Internet connection, the arrangement is called a dedicated T1 Internet connection. Dedicated means that the full bandwidth is always available for your use only.

The most direct competitor to T1 is now Ethernet over Copper or EoC. Ethernet over Copper uses the same twisted pair telephone wiring that T1 lines use. The main difference is that the equipment on each end uses a more advanced technology to transport higher bandwidth through each copper pair. Often multiple pair in the same binder cable are used to bring in a higher bandwidth EoC service.

Ethernet over Copper is available is bandwidths from 1 Mbps on up to typically 20 Mbps. In some areas, it is now possible to get speeds as high as 90 or 100 Mbps delivered over copper pair. Those are bandwidth levels that have demanded fiber optic connections until recently. EoC is also designed to be highly scalable. You order and EoC port at the speed you ultimately expect to need but only sign up for the speed you need now. In the future, you can have that speed raised by simply calling your service provider and the change will be made in days or even hours.

A comparable service priced the same as a T1 line is 2x2 Mbps Ethernet or 3x3 Mbps Ethernet. Those designations mean that you get the same speed for upload and download, just like with a T1 line. Note that the bandwidth is as much as twice as high, however.

The third option is business class Cable broadband. This service is offered by Cable TV companies, such as Comcast, that also provide consumer broadband. The coaxial cables used for Cable TV have tremendous bandwidth capacity and can easily transport broadband as well as television signals. You connect via a Cable modem. The latest Cable modem standard is DOCSIS 3.0 that can deliver 50 or 100 Mbps to business users.

It may seem amazing that you can get 50 or 100 Mbps for the same price as a 1.5 Mbps T1 line, but there are some differences in the services. Cable bandwidth is shared, not dedicated. You’ll find that your bandwidth varies during the day depending on how heavily other users are uploading and downloading. Also, Cable bandwidth is not symmetrical. You may be getting 100 Mbps in the download direction, but your upload path will be only 10 or 15 Mbps. That may not matter if you are primarily accessing Web pages or watching video clips. It could be a problem if you expect to be transmitting video service or uploading very large files frequently.

Cable does have one extra advantage in that you can get what’s called a “triple play” service. That’s broadband, telephone and television all on the same cable for one bundled price. This is especially attractive to businesses that have waiting rooms for the public, like doctor’s offices or auto service facilities. There are special bundle prices for public businesses like bars and restaurants.

Which bandwidth solution is best for your business? Why not get prices and availability for Cable broadband, T1 lines and Ethernet over Copper for your business location? Then pick the solution that makes the most sense for your applications.



Note: Photo courtesy of Wikimedia Commons.