|Managed Networks: Enabling Predictable QoS
BY MIKE KATZ
In the premiere issue of INTERNET TELEPHONY, I made some predictions about the
future of IP telephony. While on the surface those theories might appear aggressive, theyre certainly not
any more aggressive than the statements being made by companies offering managed IP
networks and services. A well-managed corporate IP network is perfect for IP telephony
applications. It offers all the glue to hold these applications together, while supporting
high (enough) voice quality. Who are the providers of managed IP bandwidth and why are
they placing their bets on both corporate and next gen IP telephony applications to drive
Managed Network DesignWhat is a managed network? A managed network is one that has
predictable performance measured in terms of Quality of Service (QoS) or
Quality of Transmission (QoT) guarantees. These latency (that is, the time
it takes to pass an IP packet from one point in the network to another) and
the ability of the network to move large amounts of packet traffic without
dropping or losing packets. When IP telephony is run across an unmanaged
network like the Internet, it is subject to network congestion on the 'Net
effects the quality of the call. A managed network provides IP telephony
applications with the predictable performance needed to be successful within
a corporation, or between Internet Service Providers (ISPs).
A managed network can be created out of existing network infrastructure; for example, a
corporations data network back-bone.
IP telephony traffic takes advantage of the existing infrastructure to connect callers
via gateways from remote branch offices to the main corporate site. The infrastructure
could include frame relay, circuit-switched, or ATM links. While this approach is simple
and straightforward, it is also expensive to implement. It is built around over-provisioning the bandwidth needed to support both the
corporations existing data applications and the toll bypass voice needs sort
of a brute-force method. In addition, to be truly successful, it requires performance guarantees from the
intranet provider. Fortunately, Sprint and AT&T have already begun to offer
performance guarantees on their backbones latency. This approach works best when the
needed bandwidth is either already there or relatively inexpensive to add.
Another managed network design more complex and potentially more efficient
involves the use of a concept in the IP networking world referred to as subnets.
Think of a subnet in this case as a specialized network that gets only the IP telephony
traffic, while the corporations data traffic travels via slower routes.
For example, a managed network attacks the problem
of network congestion by segregating the network into sub-networks using routers.
Basically, the idea is to ensure that adequate bandwidth is available by controlling or
limiting the traffic introduced onto a designated IP telephony sub-network. Carriers would
be able to charge more for this "first-class" service.
FIRST-CLASS BUSINESS EXAMPLES
Real-world examples of managed network suppliers include some of the best-known names
in the telecommunications markets: AT&T via AT&T WorldNet, Sprint via Global One,
MCI, and some new hot players such as Qwest Communications, Level 3, ITXC, and Genuity
(now part of GTE Internetworks).
Will some of these bandwidth suppliers also offer IP telephony service? Yes. Already
this year there have been several bold moves by some of the newer players to grab more of
the bandwidth and IP telephony carriage markets via consolidation. One of the largest
moves is being undertaken by Qwest Communications, which will acquire LCI International in
a stock swap valued at $4.4 billion. The merger will create the fourth-largest
long-distance company in the United States. The marriage of the two telecommunications companies combines Qwests fiber
network, which is set up to run IP data and Qwest has published plans to sell both
bandwidth and IP telephony services with LCIs sales and marketing expertise,
distribution channels, intelligent network platform, customer service, and billing system.
So, the fourth-largest long-distance/band-width provider will be building out an IP
telephony service to be priced at 0.75 cents per minute.
The traditional market players such as AT&T are not taking this new entrant lightly
either, they have announced their own plan to offer domestic IP-based debit card service
with a 0.075 to 0.09 cent a minute rate by midyear. There has been a great deal of discussion about the arbitrage opportunities for next
gen telcos to provide cost-effective toll bypass applications for businesses and why this
opportunity is relatively short -lived. In fact, some analysts predict that it is only viable for the next one to two years.
Part of the reason for this short market window is the fact that Internet Telephony
Service Providers (ITSPs) customer pricing will be nearly matched by the
existing Inter-Exchange Carriers (IXCs) and, internally, they both must pay similar
termination and settlement charges.
MANAGED NETWORKS A BUSINESS JUSTIFICATION
If traditional long-distance provider pricing becomes low enough, then the only real
value in IP telephony for a corporation can be found in adding applications in-house.
So, will corporations have to purchase gateways and create or revise their own networks
to reap the benefits of IP telephony applications? The answer is "Yes," to
purchasing gateways, and "Perhaps," to rebuilding their corporate networks. For
a corporation with excess capacity on its existing data networks, the real expense to
implementing voice over IP is in purchasing IP gateways.
The case for a corporations decision to deploy IP telephony versus pay for IP
telephony minutes is very compelling. Because the IP telephony gateway is on company
premises and uses network bandwidth that is procured at a fixed price, it will almost
always be less expensive than paying for minutes through either an IXC or an ITSP. As
discussed above, there are bandwidth providers today that will provide a corporation
either a heavily provisioned corporate intranet or create a subnet out of the service
providers network with performance guarantees to ensure IP telephony traffic
passage. Therefore, business customers now have the justification and means to deploy
cost-saving IP telephony.
Managed corporate networks are the "backbone" of corporate IP telephony.
In the last several months, more than enough key bandwidth suppliers have emerged.
Deploying gateways and judicious use of these bandwidth suppliers resources can save
companies real money.
Mike Katz is vice president of marketing and business development at NetPhone, Inc.
Headquartered in Marlborough, Massachusetts, NetPhone is a leading provider of computer
telephony solutions for small business environments. For more information, contact the
author at [email protected].