Point to Point Dedicated T1

A classic telecom service that is still going strong is point to point dedicated T1 service. Let’s have a look at how it works and what you can use it for.

T1 lines were originally developed by the telephone companies for their own use. The idea was to consolidate 24 separate analog phone lines into a single digital trunk. The key features were serial digital transmission over no more than two twisted pair, regeneration to extend transmission distance indefinitely, nailed-up private line connections between two locations, a multiplexing scheme to keep the 24 simultaneous conversations separate and distinct, and a line speed of 1.5 Mbps.

This legacy service is still widely available and is called T1 telephone or T1 CAS for Channel Associated Signaling. It is used to connect business PBX telephone systems to telephone service providers for outside lines. Most businesses can get easily get by with 24 outside lines, so only a single T1 line is needed. There is a newer version of this service called ISDN PRI or T1 PRI for Primary Rate Interface. The underlying T1 line works the same. What’s different is that one channel is reserved for switching, dialing and data such as ANI or Caller ID. That leaves 23 outside telephone lines on one T1 PRI, still right for most small and medium businesses. Larger companies and telephone intensive businesses such as call centers can order multiple T1 PRI lines to gain more outside phone lines.

The designated T1 line speed of 1.5 Mbps, chosen to support existing telephone infrastructure, made it very attractive as a way to connect businesses to the Internet and for connecting company networks across long distances. Companies became more and more computerized with terminals and later PCs on every desktop. Internal networks eventually standardized on Ethernet as a network protocol and speeds increased to 10 Mbps, 100 Mbps and 1,000 Mbps. In the early days, even larger companies used dial-up modems for file transfers. Dedicated lines ran at 64 Kbps and 128 Kbps. That was fine when data files were small, few and far between. It wouldn’t work anymore when data moved from paper to disk files.

The trick to using a telephone-inteneded technology as a digital private line is to treat the entire line bandwidth as a single entity and ignore the 8 bit increments that define individual telephone channels. This is a clear channel pipe arrangement. You’ll need a router to connect to your network and a T1 interface card for the router. Plug this into the T1 “smart jack” installed by the service provider at each end of the line and you’ve got a 1.5 Mbps data connection.

A valuable characteristic of point to point T1 data lines is that they are permanently connected or “nailed up.” The actual wires, one or two twisted pair of telco wiring, are assigned to your T1 line and nothing else. No one else can gain access like they might on the Internet. This is what makes the dedicated line both dedicated to your use and private. The line goes from point A to point B and nowhere else.

What if you want to connect to another location? You can either cancel the T1 line you have now and get a new one going to that other location, or add another T1 line so you can connect to both the current and new location. You can add as many T1 lines as you like, but they all only go between two locations. What some companies do is create their own private network by running point to point dedicated T1 lines from each branch office back to headquarters. Then they set up a star network with HQ managing all traffic between the branches and headquarters and from one branch to another.

What if you like the idea of dedicated point to point service but really need more than 1.5 Mbps? That can be achieved by bonding T1 lines to double, triple or gain up to 12 Mbps of line speed. You can also use T3 lines (DS3 bandwidth) instead of T1 for 45 Mbps of bandwidth or SONET fiber optic lines starting at 155 Mbps. An alternative is Carrier Ethernet E-Line which gives you point to point Ethernet connections from 2 Mbps on up to 10 Gbps.

Can your business make good use of point to point dedicated T1 lines or higher bandwidth services? If so, get prices and availability on the line services right for your company.




Note: Picture of twisted pair cable courtesy of Wikimedia Commons.

Call Center Contact Center Phone Service

Call centers and contact centers are major users of telephone services, especially long distance and toll free number services. What’s the best option for your call center to ensure that you have the right features and the best pricing? Well, there are several good technical options available right now. Let’s take a closer look at them to see what they can offer.

Traditional telephony has been based on basic business phone service, also called POTS or Plain Old Telephone Service. Old is right. Analog phone lines have been used for over 100 years and are still going strong. They’re highly reliable, deliver clear voice quality and don’t suffer from digital artifacts like latency.

Analog lines were originally intended to be one line per telephone. Key systems allow multiple lines on each phone so you can select which one to answer manually. All the but the smallest call centers have more lines and more agents than a key system can handle. That means using a PBX or Private Branch Exchange to automatically assign lines and direct incoming calls.

What PBX offers is automation. If you only need a half dozen or so outside lines, analog business lines still make economic sense. You connect them to your PBX using FXO (Foreign Exchange Office) ports on interface cards that plug into your PBX system.

When you need more than a half dozen or so outside lines, digital trunk service starts to make sense. Why? It’s because there is a cost advantage to bundling multiple phone lines into one trunk line. You may already have multiple analog lines coming in via a multi-pair binder cable. This is different. A T1 line uses two twisted copper pair to carry 23 or 24 separate phone lines digitally. Yes, those are the same copper pair that would otherwise be used for analog phone service.

The way this works is that the phone conversations are digitized at one end using an analog to digital converter and converted back to analog at the other end using a digital to analog converter. Each call is assigned its own digital timeslot or channel. They are kept separate so that there is no cross-talk between calls. T1 is a synchronous system that has strict timing at both ends of the line. Latency is almost non-existant. However, any unused channels are transmitted empty. All channels are constantly being exchanged between your PBX and your telephone service provider.

Why the choice between 23 and 24 phone conversations on a T1 line? All 24 channels can be used for telephone calls. This is called a T1 telephone line or T1 trunk. The other option is to use 23 channels for conversations and use one channel for switching, signaling and data, such as ANI and Caller ID. That option is called ISDN PRI or T1 PRI. PRI trunks are very popular with call centers because they offer the Caller ID information and faster switching times than normal T1 phone lines. Your PBX system may have multiple PRI ports so that you can have 23, 46, 69 or more outside lines for your call center.

SIP Trunking is an alternative to ISDN PRI. It is based on VoIP technology and uses packets rather than channels. SIP Trunks can be interfaced to older technology PBX systems and the newer IP PBX phone systems. There may be cost advantages for SIP Trunking, especially if using a lower bandwidth CODEC (Coder/Decoder) than the industry standard G.711. Some newer CODECs offer high call quality while transporting more simultaneous calls on the same line bandwidth.

SIP Trunking also opens the opportunity for cloud communications or Hosted PBX. With a hosted system, both the outside lines and the PBX switching system move to the cloud. You have only phones and a VoIP gateway in-house. The advantage to a cloud hosted solution is that you avoid heavy capital investment, pay for service by the agent seat per month, and don’t have to worry about maintenance or upgrades. The service provider takes care of all this for you.

Are you starting up a new call center or contact center, facing an upgrade cycle or expanding operations? If so, this is the perfect time to check business phone service options and prices for call centers and contact centers. You could gain performance advantages at lower prices now.

Who Still Needs a T1?

With all the hoopla over copper and fiber Ethernet, plus new options in Cable broadband, that stalwart of business connectivity, the T1 line, is getting little fanfare these days. Does that mean that T1 is on its last legs? Or, is there a future for this proven telecom service?

Far from fading out, T1 is as popular as ever. New installations are being provisioned as you read this. The fact that T1 has been around for decades is one of its strongest features. That and the decline of T1 prices in tandem with competing Ethernet over Copper services are keeping T1 in the game.

So, who really needs T1? You do if you need professional grade dedicated bandwidth, secure point to point connections, or robust telephone trunking. That’s especially true if your business location is a bit off the beaten track. If you can’t get any wireline service other than plain old telephone, you probably can get a T1 line installed.

T1 has almost universal connectivity today. To understand how that can be when DSL and Cable rarely go past the city limits and Ethernet services are mostly found in business districts, we have to look back at why T1 was developed in the first place. We think of T1 lines as wide area network connections today, but in the beginning T1 was a telephone trunking system.

Prior to WWII, telephone companies connected to each other through analog lines on telephone poles or underground cables. Carrier telephony used a frequency division multiplexing scheme to load multiple conversations onto a single pair. In the 1950’s, Bell Labs developed digital multiplexing to replace the analog systems. The basic digital trunk was defined in the T-Carrier specifications. T-Carrier includes T1 and T3 lines.

The genius behind the design of T1 is that it runs on two pair of ordinary twisted pair copper. This is the subscriber loop connection that is installed in every business for telephone service. The wires are the same, but the signals on a T1 line are digital, not analog. While one copper pair can carry one business phone line, two copper pair can carry 24 phone lines or a digital bandwidth connection of 1.5 Mbps.

Another smart thing about the design of T1 is that provisions were made to boost the signal so that it can connect far flung locations. Not every business location is within a few thousand feet of a telco central office. Even analog signals fade out with distance. The much higher digital signal frequencies fade out much quicker. That’s why DSL is hard to come by. Unless you are close to the phone company CO, the DSL signal has little bandwidth capability left by the time it gets to your place.

The T1 support system was designed with a device called a regenerative repeater that can be installed in the line every mile or so to complete regenerate the signal. The noisy and faded input signal is boosted and reshaped so that at the output it looks like what comes out of the central office. Keep adding these repeaters and you can extend T1 service far out into the countryside.

If you have a business on the edge of town or in a remote location, you may still be able to get a T1 line for a reasonable price. The only real competition is two way satellite broadband. It works, but has very long latency times that make telephone service perform poorly, is subject to rain and snow outages, and has download limitations. If you exceed your quota, your speed will be reduced so that you don’t hog the limited resources of the satellite.

T1 has none of those problems. You get a rock solid 1.5 Mbps in both the upload and download direction. Load it full up with data transfers 24/7 or use what you need, the price is the same. Latency is negligible for most applications. In fact, T1 works great as a multi-telephone service or in the ISDN PRI configuration that supports most PBX telephone systems. You don’t have to get an Internet only data connections. T1 lines can be ordered between two business locations for a private line connection.

Is T1 the right service for your needs? Check T1 prices and availability instantly and compare with other options... if there are any that are suitable.