Wide Area Computer Networking

Local Area Networks are ubiquitous for computer interconnections in both large and small businesses. The speed of the network is 10 Mbps Ethernet, 100 Mbps Fast Ethernet, 1 Gbps Gigabit Ethernet, 10 Gbps 10 Gig-E or some combination of these. Backbone links to entire floors or buildings may run over optical fibers at gigabit rates, while drops to desktop workstations may need to be no faster than 100 Mbps. But how do you extend your network across town or across the country?

Network design over long distances is called Wide Area Networking. That wide area might be to neighboring towns or it could include facilities on the other side of the country or even International connections. WAN network connections come in a variety of protocols, availability and costs.

The most common broadband networking is using the Internet as a WAN with almost unlimited connections. To do this, you need a broadband drop from an Internet Service Provider for each of your locations. These can be DSL on the low end or, more typically, T1 lines for guaranteed reliability. Since the Internet is basically a public commons, you'll want to encrypt your data with VPN software to create a Virtual Private Network within the actual public network.

True private lines give you control over the traffic on your WAN connections. You can engineer your wide area network design to control such parameters as packet congestion, traffic priorities, and latency. If you need more throughput, you can upgrade to a higher speed line or bond additional low speed lines together to gain more bandwidth.

There are a number of different network protocols that serve WAN users. Traditional TDM or time division multiplexed trunks are tightly synchronized to keep data channels in their assigned time slots. T1 lines are an affordable solution for dedicated Internet connection or private point to point lines. A T1 line will give you 1.5 Mbps full duplex. That's generally enough for typical business electronic data Interchange. You can bond these lines together to increase bandwidth to 3, 4.5, 6 or more Mbps.

Higher speed TDM based lines include T3 carriers running at 45 Mbps and optical carriers, such as OC3 at 155 Mbps. OC3 can easily transport 100 Mbps LAN to LAN data. Higher speed lines such as OC12 offer 622 Mbps and OC48 offers 2,488 Mbps.

Newer metro and wide area fiber optic networks operate as IP networks rather than TDM. They are essentially Ethernet networks that encircle a town or go from point to point between cities and states. Since your packets stay in the IP format as they enter, traverse, and leave the network, you can manage an Ethernet, Fast Ethernet or Gigabit Ethernet WAN connection as an extension of your LANs.

Another specialized WAN protocol is Frame Relay. This is a privately run shared network that provides point to point or mesh connections over long distances as virtual private connections with committed information rates.

Which WAN solution is best for your business? Our technical support team is happy to discuss your needs and find the lowest cost carriers that meet your speed and reliability requirements. You'll find our easy to use WAN inquiry form.

What is ISDN?

ISDN stands for Integrated Serviced Digital Network. It's an internationally standardized telecommunications service that was originally designed to support voice, data and video services for home and business users. Today the low bandwidth consumer version of ISDN has all but disappeared. Business telecom services over high bandwidth ISDN are alive and well, and are particularly advantageous to dial-up ISPs and call centers.

ISDN is based on the concept of 64 Kbps digital channels. That number is not arbitrary. It is the original channel size for a digitized telephone call of 8 bits sampled 8,000 times per second. Sound familiar? That's the standard chosen for T1 telephone lines. A T1 voice line has 24 channels or 24 individual telephone lines all digitized an transmitted on two pair of copper wires.

In ISDN lingo, those same channels are called "B channels." The B stands for Bearer. What the ISDN service is bearing can be traditional voice telephony or Internet and other digital data.

ISDN also defines another type of channel called "D channels." The D stands for Delta, although it is sometimes referred to as a data channel. A Delta channel is used for signaling and control, but is sometimes pressed into service to actually carry data communications.

The low bandwidth version of ISDN is called Basic Rate Interface or BRI. It consists of 2 Bearer channels and 1 Delta channel. The B channels are 64 Kbps each. The BRI D channel is 16 Kbps. This is sometimes referred to as 2B+D.

ISDN BRI runs at a combined bandwidth of 144 Kbps, which is low enough to be easily transported on a single copper wire pair telephone line. It was envisioned as a way to improve upon dial-up Internet access, which has to convert from digital computer data to analog tones that can travel on a voice telephone line. You're lucky to get 48 Kbps on a phone line, and often it's more like 33 Kbps on a noisy line. With ISDN, one Bearer channel can be used for Internet access at a full 64 Kbps and the other Bearer can be used for telephone calls. The Delta channel controls everything. If you don't need a voice line, the two Bearer channels can be bonded to give you a 144 Kbps Internet service. For ISDN BRI you need a special ISDN digital modem.

The reason you don't hear much about ISDN BRI is that another standard, DSL or Digital Subscriber Line, was developed to provide much higher bandwidths of always-on Internet access while sharing an existing voice telephone line. It's not uncommon to get 10 times the bandwidth on DSL that you would on ISDN BRI, and for less cost.

ISDN PRI is another matter. The PRI stands for Primary Rate Interface. This is the high bandwidth version of ISDN that consists of 23 Bearer channels of 64 Kbps each and 1 Delta channel that is also 64 Kbps. Those 24 channels are delivered on a specially configured T1 line called T1 PRI.

Like a regular T1 telephone line, the Bearer channels can be used to replace individual analog telephone lines. On a regular T1 line, all 24 channels are Bearer channels and signaling is done by "robbing" bits from the datastream to provide on-hook / off-hook signaling. Phone numbers are conveyed by DTMF touch-tones on the voice channels themselves. There is no room for other services such as Caller ID.

T1 PRI changes all that. The 64 Kbps Delta channel has plenty of capacity to handle all the signaling for the other 23 channels, plus Caller ID. A common use for a T1 PRI line is to consolidate up to 23 separate telephone lines plus Caller ID for PBX telephone systems used by business offices and call centers. A T1 PRI can be cost effective in replacing as few as 10 or 12 analog phone lines. A PRI interface board in the PBX system provides the digital interface.

Another popular use of ISDN over T1 is for dial-up Internet Service Providers. The 23 digital lines can each interface to one 56 Kbps analog modem in a modem bank located near the customers. The combined modem signals are then conveyed to the distant ISP over the T1 PRI line at full digital speed.

If your business has an application that is appropriate for ISDN PRI service, our technical consulting team is happy to assist you in finding the best value in T1 PRI service for your location. There is no cost or obligation for this service. Visit T1 Rex to request a complimentary T1 PRI quote now.

Colocation Bandwidth Advantages

If your Internet access, hosting and other telecommunication needs have started small and grown steadily over the years, you probably have your own data center. The big advantage of an on-site data center is quick and easy access to your server farm and network connections. But, you also have the responsibility of physical security, environmental controls, backup power and wide area network connections.

Another approach is to move your equipment to a "colo" or colocation center, also called a carrier hotel. This is a special facility where many companies and telecom carriers rent space and provide access to each other's networks. The colocation center operator provides physical security for the building and network wiring, environmental controls, battery and generator power backups.

So why buy these service when you can provide them yourself? One good reason is that you may have more choices among telecom carriers that you have at your location. Numerous Internet service providers and long lines carriers may offer points of presence in the same facility. Not only does this create competition for bandwidth pricing, but you may be able to get service from companies that can't directly connect to your location. That's especially true if your operation is not sited within a major metropolitan area.

Telecom services may include T1, DS3, OC3, OC12, and OC48 TDM voice and data service. You may also find easier to get IP services such as Ethernet, Fast Ethernet, and Gigabit Ethernet. A carrier hotel is likely to have multiple fiber optic cables brought into the facility. How many fiber optic cables service your facility?

Colocation bandwidth is sometimes available by the megabyte or gigabyte instead of a fixed bandwidth available elsewhere. You may also have the option to quickly increase or decrease the amount of bandwidth that you are buying, since the carriers have routers and switches in the same carrier hotel. The colocation center usually has a "meet me" room where carriers all locate their equipment, or at least patching facilities to make connections quickly, easily and cheaply.

Another advantage is the ability to get redundant network connections from diverse carriers. In other words, you buy some of your bandwidth from one carrier and the rest from a competing carrier. If one carrier has technical problems that disrupt your service, you'll still be able to run on the bandwidth from the other non-related carrier. You can get redundant services brought to your own facility, but it's likely a lot more expensive and less flexible. Latency within a colocation center is reduced, too, since you are located within feet rather than miles of your bandwidth providers.

You may also want to consider a colocation facility for disaster protection. What happens if a fire, flood, hurricane, tornado, earthquake or other disaster hits your facility? By having at least a backup facility at a remote colocation center, you'll be able to keep running regardless of local emergencies.

If you'd like to compare bandwidth pricing available at colocation centers or direct connections to your facilities, get a quick, no obligation quote.