Pseudowires Enable TDM Services Over IP Networks

It's no secret that packet switched networks are the technology wave washing over the telecommunications industry. The main obstacle to a world of everything over IP is an entrenched infrastructure of TDM or Time Division Multiplexing networks. It took 50 years for TDM technology to permeate every nook and cranny of telephone and long haul data networks and it's not about to go quietly. Why should it? TDM services such as T1, SONET and ISDN PRI telephone trunks offer high reliability and extremely competitive pricing.

While both service providers and business users want to protect their enormous investment in PBX and networking equipment, carriers are looking to implement new networks as native IP networks, including Carrier Ethernet and packet based DWDM fiber optic networks. If TDM and other native services, such as ATM and Frame Relay, could be readily transported on the newer MPLS networks, then carriers would be free to migrate from their legacy TDM technologies to a new standard protocol. A technology that enables just this is called pseudowires.

What is a pseudowire? The name implies something that is a wire of sorts. Indeed, this is the intention. Only pseudowires are not physical copper wires or fiber optic cables in themselves. Instead, a pseudowire is something of an abstraction. It is an emulation of a hardwired connection between two points. Ideally, you should not be able to tell whether your signal is traveling over a pseudowire or a dedicated line. Your signal is encapsulated by the pseudowire at the ingress point and returned to its native format at the egress point.

You'll find pseudowires implemented on packet switched networks, especially MPLS networks. MPLS itself was designed to carry a variety of protocols. Hence, the name Multi-Protocol Label Switching. Ethernet and IP networks can also implement pseudowires to carry a variety of TDM traffic, such as T1, E1, T3, E3. This is often referred to as TDM over IP or TDMoIP, developed by RAD Data Communications. Pseudowire specifications are defined by the IETF (Internet Engineering Task Force) and the ITU (International Telecommunications Union) among others.

Merging time division multiplexed and packet based networks presents some formidable challenges. TDM is a strictly timed and partitioned service with precisely multiplexed channels in the datastream. Packet networks lack this strict clocking and are based on individual packets rather than timeslots. TDM over IP requires that timing information be preserved by using highly precise clocks at each end of the line or derived from the data bit rates themselves. The channelization structure must also be transported on the network so that the packets can be converted back into voice or data channels at the far end. Any packet loss must be concealed by substituting fixed or interpolated data to fill in the bitstream.

Pseudowire emulation offers a convenient way to re-engineer networks from switched circuit to packet based without having to re-engineer the myriad of user services that run on the network. This way customers can preserve their substantial investment in PBX phone systems and other TDM network equipment until it makes economic sense to convert to Enterprise VoIP or Carrier Ethernet WANs.

What networking technologies make the most sense for your organization? Our team of experts would be delighted to review your current and planned needs and offer the best options for point to point private lines, telephone trunking, and point to multipoint connections to multiple business locations. Get in touch with us anytime per the online or toll-free contact options at T1 Rex.

BlackBerry 8800 Productivity Device for Cingular

The newer generation of BlackBerry devices features slimness and multimedia. Perhaps there is a bit of show business spirit in the design center. Or perhaps it's just a realization that both form and function need to be considered in a mobile wireless productivity device. The BlackBerry 8800 has both the form factor and the useful functions that will be appreciated by business and tech users alike.

This particular implementation of the BlackBerry design supports the Cingular network. It's a GSM quad band world phone with high speed download using EDGE cellular broadband technology. That gives it bandwidth up to 144 Kbps, more than adequate for email and small screen Web activities. A unique feature is support for Cingular's push-to-talk or PTT walkie-talkie services. PTT is handy for quick verbal communications back and forth. You go back to regular full duplex cellular phone service for those longer conversations.

BlackBerry made its name on text-based communications and this model offers full support. You get the BlackBerry email client that can integrate with up to 10 accounts for business-secure transmissions. You can view business document attachments in Microsoft Word, Excel and PowerPoint formats. BlackBerry Messenger also comes preloaded for instant messaging. Messaging is made painless with the full backlit QWERTY keyboard. Screen navigation is by trackball like the BlackBerry Pearl, replacing the previous track wheel.

Other on-the-go applications include full HTML Web browsing with bookmarks and BlackBerry Maps support. GPS locator is included as is Telenav. The digital assistant is becoming a navigation system as well.

Multimedia features include the ability to download and play audio and video files in MPEG4 or H.263 video and MP3 or AAC audio. Multimedia messaging is supported with add-on plans to the basic wireless service. Built-in memory is 64 MB, but you can add more by plugging in MicroSD memory cards. Note that this model doesn't include a camera. That makes it acceptable in many corporate environments where cameras of all types are prohibited.

Don't forget that the BlackBerry 8800 is also a cell phone. It includes Bluetooth wireless technology so you can clip a wireless headset on your ear and put the BlackBerry in your pocket. Or turn on the speakerphone for group conversations.

This new BlackBerry is no brick. It's svelte dimensions are 4.5 x 2.6 x 0.6 inches, with a weight of 4.7 ounces. The battery has enough power for up to 300 minutes of talk time and up to 578 hours on standby.

What are the hottest cell phone deals available right now, including free cell phones? Use the Cell Phone Plan Finder to check out the top phones and associated wireless service plans.

Copper is Dead. Long Live Copper Lines

Those who predict the future of technology long ago figured that the Earth would have all but reclaimed the copper metal in telecom cabling by now. Copper wiring is so positively 19th century, so Alexander Graham Bell, so Samuel F.B. Morse. Why, nobody will still be using copper wire to transport the high technology signaling of the 21st century. Yet, it's still here and still the subject of intense research. Why is that? Are telecommunication companies allergic to glass fibers, or just short-sighted?

Actually the death of copper wiring for both in-plant networking and metro access was very prematurely announced. It's here and it's staying for a very good reason: cost. Nowhere is this more true than in what's called "first mile" access. While the cost to trench or pull fiber optic cabling to building can run into the thousands or tens of thousands of dollars, using copper bundles is almost a freebie.

Why? Because it's already there. Messrs. Morse and Bell kept us hopping to wire the world over the last 150 years. Wire it, we did. We mined, refined and reburied mountains worth of copper metal to an extent that nearly every building has at least a couple pairs of telephone wire. Clever technology has let us use these installed pairs to carry both analog voice conversations and high speed digital network data.

Consider farms, ranches, cellular towers and industries in rural areas. Who is going to pony up the capital to trench fiber optic cables dozens of miles in the middle of nowhere? You need a good size business with a critical demand for fiber optic bandwidths to justify the cost. On the other hand, if all you really need is low to medium Mbps bandwidth for point to point or dedicated Internet access, chances are that the first mile or first ten miles of access are already in place. It's just a matter of fairly routine engineering to re-purpose those copper pairs from analog to high speed digital.

The most popular commercial digital telecom service readily available today is T1 line service. It offers 1.5 Mbps both upload and download. This digital bandwidth can be used to carry up to 24 separate telephone lines or can be configured as a data pipe. It's a private connection between facilities. Alternatively, it can provide broadband Internet service for up to 25 users. What if 1.5 Mbps isn't enough bandwidth? Multiple T1 lines can be bonded together to act like a single larger bandwidth service in multiples of 1.5 Mbps. Each line service requires 2 copper pair, so if you have enough pairs bundled to your location you can often get 3, 4.5, 6, 7.5 or 9 Mbps. Higher rates are also possible if copper is readily available and new fiber installation is too onerous or expensive.

So have we tapped out copper's capability? Not really. The IEEE (Institute of Electrical and Electronics Engineers) established a working group that's establishing new standards for using copper as a first mile access technology for Ethernet metro and wide area networks. The IEEE 802.3ah is embracing both fiber and copper in the physical layer. There are two new standards for increasing the speed of copper transmissions. 2BASE-TL offers a minimum of 2 Mbps over distance of up to 9,000 ft with a nominal speed of 5.7 Mbps. Up to 8 pairs can be readily bonded to deliver similar bandwidth to a T3 line, which runs at 45 Mbps. The other standard is 10-PASS-TS. This is a shorter range technology that delivers a minimum of 10 Mbps up to 2,460 ft. 10-PASS-TS also supports pair bonding to increase bandwidth. Hatteras Ne7works and Actelis are two major suppliers of equipment to meet these new standards.

As Carrier Ethernet gains strength for wide area networking, the EFM or Ethernet in the First Mile standards from the IEEE seem like a good match for access to the metro and long haul networks. With only an estimated 11% of buildings currently wired for fiber optic access, it's likely that improved modulation techniques will extend the life of already in place copper cabling for years, if not decades to come.

What technology is right for your commercial application? Our expert consultants would love to take a look at the options available for your location or locations and put together a highly competitive quote for service. Find the best prices on copper and fiber optic line services now.

Compare Broadband Service Offers

Interested in moving up from dial-up modem service to broadband for your home or home office use? Wondering if there are better bandwidth options at lower prices? With the speed that technology is changing, it can be hard to know what your best deals are. What you need is a search engine that allows you to compare broadband service offers instantly. Well, we've got one for you.

Can I Get DSL? It's not just a question, it's a tool to find all sorts of broadband Internet services. You may be surprised to know that broadband, unlike dial-up, is very location specific. Your neighbor across the street might qualify for DSL while you can't. You might be able to get cable modem service, while down the street they're out of luck.

There are three main categories of broadband service available for residences, with a couple of long shots. The long shots are wireless or WISP services that are strictly local and depend on your ability to see the tower from your house. Fiber optic service is the fastest you can get at a very reasonable price, but it's only available in a few Verizon service areas right now.

Most everyone else will qualify for one of the three major broadband delivery systems. DSL or Digital Subscriber Line is offered by phone companies or companies such as Yahoo in partnership with a phone company. DSL rides on your telephone line as a high frequency signal originating at your local telco office. It shares the phone line so you can still use your phone as usual. The DSL modem is always on and ready to provide you with broadband service that is 10x or more what you get with dial-up. However, just because you have a phone doesn't mean you can get DSL. Its high frequency signals only travel a few thousand feet, much shorter than telephone calls. You have to specifically check to see if your location can get DSL.

Cable modem service or Cable Internet is a broadband service that shares the cable TV line. If you can get cable TV, chances are that you can get Cable Internet. Of course, if the cable service provider hasn't run lines to your area you won't qualify for this type of broadband. Cable Internet is also an always-on service and uses a special cable modem that you buy or lease from the Cable TV company. Or you can buy your own at a major electronics retailer. Check to see if you can get Cable broadband.

What if you live in an outlying subdivision or a rural area too far from the phone company and nowhere near cable television? Your answer is two-way satellite. This service uses a small satellite dish on your roof or a pole, just like satellite TV. But this system has a transmitter as well as a receiver so you can both upload and download Internet data. The beauty of satellite broadband is that it works just about anywere in the U.S. that you have a clear view of the southern sky and power to run the satellite receiver. The receiver doesn't take much, so you could run it on a generator or solar panels with batteries. See what's available in two-way satellite broadband now.

What high speed Internet deals are available? You'll have to compare broadband service offers to find out. The offers are very competitive and change often. If you are lucky enough to have DSL, cable and satellite all available, you can choose the best value for the bandwidth you need. If you live farther out, know that satellite broadband prices have been reduced recently and can be a better deal than a second phone line with dial-up ISP service. Not to forget the much higher speeds and always-on availability that you get with broadband Internet service.

Please note that residential broadband services are the most reasonably priced for home office users and general home use. If your business has its own commercial location, you'll need commercial telecommunications services, such as T1 dedicated Internet service.

ISP Fiber Optic Backbone Bandwidth Deals

Internet service providers supply connections to the Internet along with value added services such as email and Web site hosting. But ISPs also need Internet connectivity themselves, in massive quantities at reasonable prices. The cost of bandwidth is likely the highest business expense for providers. By reducing the cost of their backbone bandwidth supply, service providers can offer more competitively priced broadband connections or improve their bottom line.

ISPs come in all sizes, from small localized operations to huge MSOs or Multiple System Operators with tens to hundreds of thousands of customers. At the low end are WiFi hotspots, apartment and commercial building networks, and neighborhood associations. These operations serve from a few to a few dozen user on a free or shared cost basis. Often a single T1 dedicated Internet line or a few T1 bonded lines are the most cost effective solution to provide the bandwidth required at this level.

The T1 dedicated Internet line provides 1.5 Mbps upload and download capacity. It can be thought of as a backbone for these very small Internet services, but it doesn't directly connect to the Internet itself. Instead, this line connects to a Tier 1 provider who does have a direct peering connection to the actual Internet or to a Tier 2 provider who buys bandwidth from a Tier 1 provider. Does this sound complicated? It's actually a similar model to the distribution of products from manufacturers to distribution centers to wholesalers and then to stores.

Intermediate size Internet Service Providers offer dial-up modem services or broadband over telephone lines, wireless towers, or through the Cable Television network. A single WISP tower or modem bank might still be served by a T1 backhaul line, but the provider's backbone connection to the Internet will most likely need 45 Mbps DS3 bandwidth or higher that is only practical with fiber optic line services. How much bandwidth is needed depends on the number of subscribers, the bandwidth offered per connection, and the level of oversubscription. Oversubscription assumes that not all users will be online consuming maximum bandwidth at any given time. This statistical multiplexing allows providers to share their backbone bandwidth among ten times as many users, or even more.

Fiber optic Internet bandwidth from Tier 1 and Tier 2 carriers has become more plentiful and and more competitive than ever. Numerous companies have their own fiber optic networks at the OC48 (2.5 Gbps) and OC192 (10 Gbps) level, typical of the Internet's fastest connections. Local access is readily available at the OC3 (155 Mbps) and OC12 (622 Mbps) to provide backbones for Internet Service Providers, who will then distribute the available bandwidth among their customers. Higher speed connections are available in the largest metropolitan areas.

Fiber optic carrier services are highly reliable, but ISPs will often opt to reduce their risk of outages even more by connecting to multiple diverse carriers. If they need several OC3 lines worth of bandwidth, they may have them delivered on separate fiber optic cables as drops from different carriers running in different directions. This way, a single cable break due to construction activity or natural disaster will slow but not cut off Internet service.

What cost savings can Internet Service Providers reasonably expect to achieve with today's competitively priced carrier bandwidth services? Our consultants are anxious to discuss your particular needs right now. See how much you can save on ISP copper or fiber optic backbone bandwidth through our GigaPackets service now.

Do You Know Registered Jack?

You're no doubt quite familiar with the terms RJ11, RJ45 and perhaps RJ48. You'll immediate recognize them as the connectors used for telephone and networking equipment. But do you realize that these aren't mere catalog numbers or even de facto industry standards. They are part of a official telecommunications standard in the Code of Federal Regulations established by the FCC. They're not just connector jacks, they're Registered Jacks.

Registered Jacks is where the initials RJ come from. There are numerous RJ types, but you are only likely to run into a few of them. Each RJxx was established by a USOC or Universal Service Order Code under the Bell Telephone System. The code specifies the jack, the plug and the wiring scheme. There is also a suffix letter, such as C for flush mount or surface mount. Other letters include W for wall mount, S for single line, M for multi-line, and X for complex jack.

Let's take a look at some of the more popular Registered Jacks. RJ11 is the one familiar to both consumers and businesses. It is the interface used for single line analog telephones. A phone, computer or modem will likely have a RJ11C jack unless there is a hardwired lead and plug attached directly to the device. In the kitchen, a RJ11W is a wall mount jack that will both connect and hold a telephone set.

T1 lines are terminated in "smart jacks" at the demarcation point, usually in the telephone closet of the business. The smart jack acts as a network interface to protect the line. The user interface is most often a RJ-48C connector. This registered jack describes an 8 position jack with four active wires, one pair for transmit and one pair for receive. Two pins are assigned for cable shield integrity and two are reserved for future use.

Another T1 line connector that is used less today than in years past is the RJ48X. The "X" means complex jack. In this case it refers to shorting bars that connect the transmit to the receive pairs when no plug is inserted into the jack. The reason this is done is to loop-back the signal for testing purposes.

What's called an RJ45 connector today looks much like an RJ48, but the RJ48 is more specialized in that it has a keyed connector and a notched jack. A RJ45 cord will plug into a RJ48 jack, but not the other way around.

The ubiquitous RJ45 connector system that is so popular in networking connections today is actually somewhat different than the original RJ45 Registered Jack specified by the telephone company. The original RJ45 was a keyed connector that used two pins for signal and two for a programming resistor. This connector system is rarely seen today but the RJ45 naming convention has been adopted for a similar size connector used almost universally in Ethernet twisted pair cabling.

The correct nomenclature for the RJ45 connector we use today is an 8P8C modular connector. The 8P8C stands for 8 positions, eight conductors. In other words, all pins are connected. The wiring scheme follows one of two Electronic Industry Association standards, either T568A or T568B. T568B is equivalent to the old AT&T 258A standard, but T568A is preferred for new installations. Both standards use all 8 pins but are wired differently. Within a particular physical plant, one standard or the other is implemented. Mixing the two can cause problems with pairs being swapped at different ends of a wiring run.

Now you know Registered Jack. Well, at least a brief introduction to the subject. If your business has a need for telephone lines or computer networking bandwidth, The Get instant line quotes now.

Digital Cross Connect Systems For T1 Lines

If your organization is large enough to use more than one T1 line for voice or data transmission, you may need a way to switch traffic between lines or within the individual channels or timeslots of your channelized T1 lines. The device that does this is called a DCS or Digital Cross-Connect System. They are also sometimes called DACS or Digital Access Cross-Connect Systems after a term coined by AT&T for their equipment that does this function.

The DCS is a sophisticated circuit switch. It can switch entire T1 lines to other T1 lines, like you might do manually with patch panel called a DSX. One application is to change the destination of audio or video streams to broadcast stations or satellite uplinks. Another use is to reroute traffic in the event of a line outage on a particular path.

But the DCS can also reach inside the T1 lines to access each DS0 channel of the 24 TDM (Time Division Multiplexing) channels per T1. You could conceivably connect the data coming from channel 2 of one T1 line into channel 12 of another T1 line. That's useful when each 64 Kbps DS0 is unique, such as individual telephone calls from a cellular base station or a branch office PBX system. In these cases, rearranging the channels is less important than combining channels from multiple fractional T1 lines into a single full T1 line.

Cellular phone systems often use digital cross connect systems to combine telephone calls from multiple base stations into full T1 lines for transmission to the mobile switching center and on to the public switched telephone network. This is called backhaul aggregation or T1 traffic grooming. If there is too much traffic for a single T1 line to backhaul, multiple T1 lines can be connected to the DCS or a M13 multiplexer can aggregate traffic up to the DS3 level.

Branch office PBX telephone system may also face the situation of needing only fractional T1 service. At the home office, a DCS can combine phone channels to fill entire T1 trunk lines that go out to the telephone carrier.

T1 lines are used in the North America and Japan, but elsewhere in the world the standard is E1. E1 retains the 64 Kbps DS0 channels but combines 32 of these into a 2 Mbps line speed instead of the 24 channels carried by a T1 line. The voice codec protocol is also different. T1 uses Mu-law. E1 uses A-law. A T1/E1 DCS can interface between T1 and E1 lines by performing the necessary voice and signaling conversions and assigning channels so that no traffic is lost.

Fiber optic networks have their own version of the digital cross-connect system called the optical cross-connect or OXC. There are two ways to implement one of these. The OEO or Optical Electrical Optical approach converts the optical signals into electrical signals, performs the cross connect function in the electrical domain, and then reconverts the electrical signals to optical. An alternate approach is called a transparent OXC or photonic cross-connect. Individual wavelengths or entire fiber beams are switched using optical components only, so the signal stays as a fiber optic light beam through the OXC.

If you would like free consultation on optimizing your T1 or fiber optic wide area network lines, our experts would love to help you get the best value in telecom line services.

Business Broadband Sharing

Most businesses today have a need for fast, reliable Internet access. For medium size businesses and large enterprises, this is usually accomplished with a commercial grade telecommunications connection such as dedicated T1 or T3 Internet service, or even optical carrier connections. But for very small businesses such as sales professionals, consultants or even small retail shops, the cost of a high reliability telecom data line leads them to settle for lower grade solutions such as Wireless, DSL or Cable Internet. But there is a way to get both high performance and low cost Internet service. It's called broadband sharing.

On the consumer side, broadband sharing is frowned upon and often prohibited by the service providers. Get caught providing WiFi broadband for the neighborhood on your Cable Internet connection and they'll cancel your service. The reason for this is that you are not purchasing bandwidth, you are purchasing a service. The ISP may advertise download rates up to several Mbps, but these are estimates not promises. The fact is that the broadband ISP is dividing up their bandwidth among hundreds or thousands of customers. They oversubscribe or sell more bandwidth than they actually have in order to keep the cost low. The assumption is that only a portion of their customers will actually be online at any given time. If you are giving away the service to your neighbors, they not only lose a chance to sell broadband to those people but exacerbate the oversubscription problem as well.

Professional telecommunication bandwidth isn't sold that way. When you lease a T1 dedicated Internet line you get 1.5 Mbps in both the upload and download directions for your exclusive use. Order a T3 line or DS3 service and you get 45 Mbps of exclusive bandwidth. Optical carriers will give you bandwidths into the Gbps range if you need that much. The other difference is that these regulated telecommunications services come with SLAs or Service Level Agreements to ensure that your line is available when you need it, and fast repairs if there ever is an outage.

You can order a T1 dedicated Internet service for your business and use it entirely for your own enterprise. But a T1 line can actually support up to 25 users who are accessing the Web or using email. What some smaller businesses do is pool their resources and share the bandwidth of a single T1 line. This is easy to do when each business has a suite in the same building. The principal or building owner will have a VAR (Value Added Reseller) create a building network with Ethernet jacks in each suite. Wireless access points may also be installed for laptop computer and PDA access. A T1 line configured for dedicated Internet access and its associated T1 router will feed the network. If even 10 or 12 offices participate, the monthly cost per office can be comparable to consumer grade broadband offerings and perhaps even less.

There's no need to worry about running out of bandwidth. If participation gets so great that a T1 line slows down, you can bond in additional T1 lines to double, triple or otherwise increase bandwidth in 1.5 Mbps increments.

This is such an attractive option that some building owners will install T1 dedicated Internet service and include access in the monthly rent for businesses, condos or apartments. Virtual office complexes rent small office spaces or shared space to consultants and sales people who only occasionally need a desk or conference room. Shared broadband is a perfect value added solution.

Industrial parks go even further by setting up fiber optic networks to interconnect the various facilities into a high speed data network. Dedicated internet access can be provided by DS3 at 45 Mbps, OC3 at 155 Mbps, OC12 at 622 Mbps or OC48 at 2.5 Gbps. Carrier Ethernet or GigE can also be provisioned.

If shared business broadband service sounds attractive or you need additional bandwidth to meet your increasing needs, our expert consultants can help you get the best deals on dedicated Internet service.

VPN Internet Access Links Facilities

A challenge for many businesses is how to cost effectively link dozens, hundreds or even thousands of facilities into a single enterprise. This includes businesses as diverse as retailing, education, consulting, warehousing, communications and transportation, to name a few. Traditional solutions, such as point to point private lines and Frame Relay networks, have their advantages. But a newer wide area networking scheme becomes more and more attractive as the number of locations increases.

Point to point private lines offer the ultimate in availability, predictable bandwidth and ironclad security. The reason is that they are direct lines between two and only two locations. The only traffic is your traffic. These are perfect for PBX tie lines or VoIP telephony between facilities. They are also ideal for constant high bandwidth applications such as video transport. The downside is that you need a separate line between any two facilities that want to communicate. Or, you can set up a star network managed at the home office with private lines out to each site. Costs are high and increase as each new location is connected.

What many businesses really want is a mesh topology where each location is connected to a provider's network "cloud" so that anybody on the network can talk to anybody else at will. Frame Relay networks have been the traditional offering for this arrangement with private carrier IP and MPLS networks now offering similar functions. But there is another solution that can cost much less than these private network solutions. It's the public network bought and paid for as a public infrastructure. It's the Internet.

The Internet? Yes. Think about it. The Internet is as ubiquitous a communication facility as you can find. Even broadband high speed data service is available nearly everywhere by landline, wireless or satellite link. It's relatively cheap compared to other networks because it is being utilized by millions of individuals and companies. If you can work around its limitations, the Internet is your most cost effective way of linking facilities nationwide or around the world.

Technically, the Internet is never going to be as reliable and predictable as a private network. It's a public thoroughfare with anyone and everyone using it for everything from downloading music to uploading web pages, blasting email messages, making phone calls and playing games in real time. Jitter, lost bits, variable data rates and long latencies are the nature of the beast. Inherent security doesn't exist. That's what's implied by public access.

Fortunately, many applications are resilient to these issues. That's especially true if your traffic is data, including email, point of sale verification, accounting or inventory updates, EDI, faxes, email, or Web enabled commerce. TCP/IP, the primary protocol of the Internet, was designed to be robust in getting data files from point A to point B reliably. If the link slows down temporarily or a few bits are dropped along the way, the system compensates. In fact the Internet was developed as a government initiative to create a communications network that would work even with multiple failures in emergency conditions.

The one loose end is security. The answer is to encrypt your private data so it can travel on a public medium privately. You can't stop someone from intercepting your data packets, but you can stop them from figuring out what the bits represent. This is called "tunneling" through the Internet. By using encryption and decryption software at each node, you create a hybrid between a private and a public network that is called a virtual private network or VPN. There are various standardized methods for doing this, including IPsec or IP security, PPTP or Point to Point Tunneling Protocol, and SSL or Secure Socket Layer.

You can set up an enterprise VPN yourself or opt for a managed VPN solution where a provider handles the routers and security software. Each of your facilities connects to the Internet through a VPN portal using a high speed connection, such as a T1 dedicated Internet line for high reliability. With business grade connectivity prices at an all time low, this could be a good time to install a new VPN solution or upgrade your current inter-facility communications system for higher speed and/or lower costs.

Our team of expert consultants can help you pick the best solution for your company, whether you have only a few locations to tie together or thousands of business sites that need access. Simply let us know what your facility communications needs are at T1 Rex.

SIP Trunking Extends Enterprise VoIP

Enterprise VoIP phone systems are often sequestered within the corporate walls. Even though medium and large businesses have been replacing traditional TDM based PBX telephone systems with IP telephony, and even though carriers themselves are often using IP based core networks to transport voice traffic, it's still a switched circuit world. SIP Trunking provides an IP to IP conduit for voice traffic without that intermediate conversion to and from the PSTN (Public Switched Telephone Network).

Companies base their technology decisions on what will work best in their particular environment. Each organization takes a look at their current deployment of analog or digital phones, their expansion needs, desired telephony features and both capital and operating expenses. The result is ad-hoc solutions that may be anything from a key telephone system with half a dozen lines to an enterprise-wide VoIP system with thousands of handsets connected to a single converged network. Within the corporate walls, it doesn't matter what you use as long as everyone can talk to everyone else. But if you want to make calls outside of the organization, you need compatibility with the phone number you want to call.

Traditionally, that compatibility has been based on analog copper phone lines or T-carrier digital lines, such as ISDN PRI circuits. These standards were established by the telephone companies over 100 years of development. At the core of these standards is a signaling mechanism known as SS7 or Signaling System # 7. SS7 is the protocol that phone companies use to talk to other phone companies. It is the control mechanism to setup and tear down, or initiate and terminate telephone calls.

SS7 is at the heart of the public telephone system. But VoIP has its own signaling protocols. A popular one and the current favorite as the emerging standard for IP telephony is SIP or Session Initiation Protocol. An enterprise VoIP system may use SIP for signaling on the same network that carries voice, video and data traffic. The corporate IP network can transport internal phone calls between remote locations, completely avoiding the public phone system. That is, until someone wants to talk to a party outside of the company. A voice gateway provides connection to the outside telephone lines or trunks to the desired phone carrier.

What SIP trunking does is to include the phone carrier within the VoIP network. That also includes access to that carrier's Voice IP network so that phone traffic can remain as VoIP packets to VoIP enabled users without a protocol conversion. Calls to phone numbers off the network are terminated by the carrier rather than the enterprise. As VoIP becomes more prevalent, fewer calls will need to be terminated to the PSTN. The result is cost savings and other features provided by converged voice and data networking.

Is your enterprise ready for SIP trunking? Our expert Enterprise VoIP consultants would love to discuss your needs including everything from basic T1 and PRI lines through SIP trunks and optical carrier data transport.