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May 30, 2008
• Vol.30 Issue 22
Page(s) 26 in print issue
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Remote Offices: Is A T1 Overkill?
T1s Are A Dying Breed
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In the Internet’s formative years, network connections were an expensive proposition feasible only for large businesses and universities. As the power, utility, and ubiquity of Internet applications changed the IT landscape, the venerable T1 point-to-point circuit emerged as the mainstay of WANs. The bandwidth demands of central offices and data centers have long rendered the 1.54Mbps T1 obsolete for their needs; however, it’s still used at many branch offices. The advent of consumer-focused broadband technologies, such as DSL and DOCSIS (Data Over Cable Service Interface Specification), offering higher throughput at substantially lower cost, now threatens T1 obsolescence for remote office networks.
Despite numerous connectivity options, it may be surprising that there are still many T1 circuits in use. Much of this is simple inertia and complacency, according to Mark Tauschek, senior research analyst at Info-Tech, noting, “There are so many T1s installed and so many WANs are built on T1s that it is difficult to displace them.” For organizations willing to shake up the status quo, he says, “Many higher-throughput and less-expensive broadband services are widely available, so multisite enterprises stand to save big on monthly connectivity costs and improve branch-office WAN performance at the same time.”
 Common WAN Circuit Options
The most common branch office WAN services, DSL and cable, are well-known; however, other less familiar services are often available in areas lacking DSL or cable coverage. Although satellite-based services are rightfully knocked for their high latency, Bill Trussel, managing director of networking and security at The-InfoPro, notes that they are still a good option in rural areas. Fixed broadband wireless is another option for urban locations without cable or DSL service.
Newer wired services, such as Verizon’s (www.verizon.com) fiber-optic FiOS or metropolitan Ethernet circuits, offer substantially higher bandwidth, and while they are more expensive than conventional broadband offerings, they may still cost less than a T1.
Trussel says an important point to remember is that unlike a dedicated, point-to-point T1, these services connect locations to the public Internet, thus a firewall and hardware VPN is required at each remote site.
Savings From Replacing The T1
Price is the primary reason that T1s are a dying breed. Tauschek finds that T1 service costs about $500 per month and that “if a frame relay or MPLS port charge and Class of Service (CoS) is added, the cost can quickly approach $800 per month.” By contrast, broadband Internet services generally run from $50 to $100 per month; thus, converting can yield dramatic savings.
Business users should beware, though, that ISPs often charge double or more for so-called business-class broadband over comparable residential service. What do businesses get for the additional money? According to Tauschek, basically nothing, because ISPs know that businesses are much less price-sensitive than individuals. Trussel adds that business-class service may come with static IP addresses, which makes it convenient for clients making incoming connections to servers at the remote site. They may also offer a limited SLA (service-level agreement); however, the service terms and guarantees are not comparable to those on T1 circuits.
This lack of strict SLAs is the primary drawback of using a broadband ISP vs. a T1; however, both Trussel and Tauschek say that the reliability of broadband networks is still high enough for most applications. Tauschek estimates that the typical ISP achieves two or three nines availability, or five to 55 minutes of downtime per year, while a T1 is usually four nines. For businesses requiring high availability, Tauschek says that using two independent broadband circuits—say, DSL and cable—with a dual-port WAN router is a cheaper and more powerful solution than a T1 because these inexpensive appliances (as little as $200) load-balance between two WAN circuits, effectively doubling bandwidth. Trussel notes that 3G wireless data service can also serve as an effective backup circuit, with several vendors now offering routers incorporating a mobile broadband data card slot that can share both a wired WAN connection and wireless 3G service.
Where Are T1s Still Appropriate?
Tauschek feels T1s are so costly that they should only be considered in branch locations with no other options. Trussel concurs and sees T1s primarily used in large, central offices where uptime guarantees are necessary and the high monthly fees can be amortized over a large number of users. Even in these situations, newer alternatives such as metro Ethernet or business-class fixed wireless, so-called wireless T1, may be preferable.
Another scenario in which T1s often excel over their cheaper upstarts is handling real-time communications, such as VoIP. These data streams require prioritization over asynchronous communications, such as email or Web access, yet once a packet hits the public Internet, any CoS tagging is lost. Some broadband providers support MPLS (Multiprotocol Label Switching), enabling traffic prioritization for low-latency applications, over their networks. VoIP users who can’t risk spurious quality degradation should find a provider with MPLS support. According to Tauschek, “It is possible to get lower-cost services, such as DSL, into the MPLS cloud; it’s simply a matter of discussing the options with the MPLS provider. If the current MPLS provider does not offer MPLS over lower cost transport, look for another provider.”
The proliferation of consumer broadband Internet access has led to a resulting abundance of WAN options for SOHOs and branch offices. The monopoly of dedicated T1 circuits has been broken, and most businesses should turn to broadband alternatives—the performance improvement and cost savings can be significant. While these don’t offer the guaranteed service levels and availability of T1s, there are mitigation strategies ranging from dual-WAN routers, mobile broadband backup, and WAN optimization appliances to address any shortcomings. 
by Kurt Marko
WAN Replacement Recommendations
Alternatives to T1s for branch-office connectivity can save a lot of money, but switching to a new provider takes some due diligence and planning. Mark Tauschek of Info-Tech Research offers these tips when considering a WAN migration project.
Examine the options available at each branch. Ideally, one service provider would supply connectivity for all branch offices. If that’s not possible, consider a VNO (Virtual Network Operator) to aggregate services, particularly if global MPLS connectivity is required.
Don’t compromise service reliability. Consider using two lower-cost services and a dual-port WAN router if availability above 99% is an absolute requirement. This won’t work with MPLS, but if the primary MPLS link fails, it is possible to failover to a private IPSec VPN.
Don’t pull the trigger without a plan. Make sure the WAN is carefully planned out before dropping the T1s. Consider all of the implications and options available before making new commitments. Again, T1s might not disappear completely, but the cost savings are significant for every site that can be transitioned to a lower cost service.
Source: "Slash Branch Office WAN Costs: Dump the T1s"; Mark Tauschek, Info-Tech Research; April 2008. |
Remote Office WAN Options
Enterprises have a host of options for connecting branch offices to corporate networks and the public Internet. Availability is far from universal and can vary within the same city; however, one or more of these should be available virtually everywhere.
| Service | Bandwidth | Price Range | SLA Availability | xDSL (ADSL, SDSL,
VDSL/asymmetric,
symmetric, very high speed) | Variable—typical ADSL 3
to 5Mbps down, 768Kbps
up but can go higher | From about $40 per month
up to $200 per month | Variable | | Cable Internet | Variable—typical 6 to 8Mbps
down, 768Kbps to 1.5Mbps
up but can go higher | From about $60 per month
up to $200 per month | Variable | | Satellite Internet | Variable—typical 1.5Mbps down,
300Kbps up but can go higher | Starts at about $100 per month | No | | Fixed Broadband Wireless | Variable—Clearwire 1.5 to
2Mbps down, 256Kbps up
Covad up to 6Mbps,
Towerstream can exceed 10Mbps | Starts at about $50 per month;
Towerstream 8Mbps (symmetrical)
runs $1,000 per month | Variable | | Verizon FiOS | Starting at 15Mbps down,
2Mbps up going up to 30Mbps
down, 15Mbps up | From $60 per month up to $240
per month (on a two-year contract) | No | | Metropolitan Ethernet | Starts at 10Mbps (symmetrical),
up to 100Mbps or greater | Varies | Yes |
Source: "Slash Branch Office WAN Costs: Dump the T1s"; Mark Tauschek, Info-Tech Research; April 2008; with additions by the author |
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