Choosing Your Ethernet Service Provider

Inter-site Ethernet				VPLS enhances a service provider's MPLS core
A guide to choosing your Ethernet service provider				network by providing a connectionless Ethernet
Key topics				service, delivering anyto-any connectivity, and gives far
The market for Ethernet is continuing to grow, as UK				greater flexibility, scalability and cost efficiency when it
organisations appreciate the cost savings,				comes to managing traffic flows. VPLS also allows
performance and efficiency gains to be made from				multiple services to be delivered to customers over
deploying services based on this transport technology.				single rather than multiple access circuits.
Businesses that choose Ethernet-based connectivity				Adoption of VPLS will undoubtedly accelerate
for their corporate Local and Wide Area Networks				technology change, reduce IT costs and allow use of
can expect greatly increased productivity and				new applications to increase productivity. In addition, as
profitability, as well as significant competitive				VPLS is protocol independent and operates at Layer
advantage, from the capacity to introduce new				2, there is greater security for customers as the
applications and services to customers and staff.				service provider has no view of, or control over, the
When choosing an Ethernet service provider,				customer's routing of particular importance to the "high
companies need to consider a range of factors				end" corporate Enterprise.
including: the fibre-based coverage offered by the				3.2.4 Developing carrier Ethernet solutions
provider the methods used to protect, optimise and				Technologies such as Provider Backbone Transport
guarantee network performance the price and				(PBT) claim to provide Ethernet services which aim to
flexibility of deploying future services. 1 Introduction				match traditional networks delivering Quality of Service
More and more enterprises are choosing Ethernet				(QoS) and protected paths.
connectivity for Internet Protocol (IP) services %u2013				4 Choosing your Ethernet service provider
not just for their Local Area Networks (LANs) but also				Several UK service providers offer National and Metro
as a means of easily, flexibly and cost-effectively				(regional) Ethernet services, and any evaluation to
connecting geographically spread sites.				differentiate between them should consider:
Ethernet offers superior network performance at				- coverage of fibre-based local access
vastly reduced cost compared to traditional Leased				- price
Lines or services based on Asynchronous Transfer				- network performance
Mode (ATM) or Frame Relay transport technologies. It				- flexibility to add future services
makes it affordable and achievable for organisations				- terms and coverage of Service Level Agreements
of any size to create a single network that is easier to				(SLAs)
manage, provides the flexibility to grow with the				- security.
business and enables new applications to be added as				4.1 Coverage of fibre-based local access
required, simply and cost-effectively.				Ethernet services above 2Mbps tend to be provided
The tangible business and IT management benefits of				using fibre, rather than copper, line plant in the last mile.
the technology are fuelling massive growth in the				Therefore, for Ethernet services, you should shortlist
adoption of Ethernet services by UK corporations, with				operators that have deployed fibre to street cabinets
market estimates for continued growth over the next				already, thereby reducing the cost of bringing Ethernet
few years already being exceeded.				services to your business premises.
2 Business drivers				It's also important to understand service providers'
There are compelling business reasons why				ability to connect into every site in your network, which
companies are embracing Ethernet as their				depends on the number of Points of Presence (PoPs)
connectivity of choice for the corporate LAN and				they have. A service provider with more PoPs is more
Wide Area Network (WAN):				likely to have a PoP close to all the sites in your
-u2022 major cost savings				network, and therefore is more likely to be able to
-u2022 increased IT efficiency				provide comprehensive Ethernet coverage.
-u2022 improved business protection				4.2 Price
-u2022 greater productivity and customer service.				With most Ethernet services, the dedicated access
2.1 Major cost savings				circuit is generally the highest cost component, while
Integrating WAN and LAN into a single, national				shared resources such as the service provider's core
Ethernet-based LAN generates considerable cost				network provide significant economies of scale, and
savings for a number of reasons.				are a small proportion of cost to the service provider.
Reduced price & flexibility of bandwidth				The shorter the access circuit, the morelikely the
Bandwidth on Ethernet is less expensive than				service provider will be able to provide a low cost
bandwidth on Frame Relay or ATM-based networks				circuit. Therefore a large number of PoPs is a strong
and you only pay for the bandwidth you actually need.				indicator that the service provider will be able to offer
This means you can get far greater capacity for an				an economical solution.
equivalent investment %u2013 in fact, businesses can				4.3 Network performance
expect to treble their bandwidth capacity for the same				For all their limitations, ATM and Leased Lines do
price as their current Frame Relay/ATM networks.				provide reasonably high levels of performance when
Where providers offer scalable bandwidth upgrades,				measured in terms of latency, packet delivery and
you can initially set lower capacity while you determine				jitter. When replacing inter-site networks that use
your network%u2019s needs, then increase capacity				technologies like ATM or Leased Lines, it is important
as and when required, easily and cheaply, without				that the new network matches the performance of
having to replace the fibre over which the service runs.				the old, not least because users do not appreciate
You can explore the opportunity to use your greater				cost savings at the expense of network performance.
bandwidth capacity to introduce new services and				When considering Ethernet services, you should be
applications that will improve your overall efficiency and				aware of the following:
competitive edge:consolidate servers and storage				Avoid over-provisioning
networks to facilitate their management and reduce IT				With packet-based networks like Ethernet, particularly
costs Take advantage of multimedia applications to				those delivered over a shared core network, it is
improve business practices and customer service,				possible for service providers to contend their network
such as delivering interactive training courses with live				in the same way that Asymmetric Digital Subscriber
video Use Voice over IP to enhance staff productivity				Line (ADSL) broadband internet access is contended
by introducing hot-desking move to thin clients within a				to reduce the service provider's cost per customer.
web-based software architecture, saving capital				The better providers are those whose networks have
equipment costs (servers and software) and				been built with enough spare capacity in the core to
minimising hardware wastage. The reduced cost and				respond comfortably to peaks in demand throughout
greater bandwidth flexibility of intersite Ethernet				the day.
enables you to be confident that your network				Latency, packet loss and jitter
availability will be robust enough to support new				As latency, packet loss and jitter significantly impact
services, as well as increasing the performance of				the delivery of Voice and Video over IP, inter-site
existing applications.				performance should ideally match LAN performance.
Reduced hardware				Voice
As Ethernet is well-established within the LAN				Voice over IP requires low latency, low jitter and
environment %u2013 there are almost a billion Ethernet				moderate levels of packet loss and a network that
interfaces in use worldwide today %u2013 and				can also manage a high volume of small voice
increasingly being adopted on the WAN, equipment is				packets (typically 40bytes). If your VoIP traffic is going
more readily available and costs far less than the				to traverse your network more than once, such as in
traditional WAN routing equipment used to support				a 'hub and spoke' network, traffic may be routed into a
Frame Relay/ATM based networks.				hub site and back out to a branch (or spoke) site. In
By enabling you to consolidate your WAN into a single				this instance, the latency, jitter and packet loss that
network, you can make major savings by eliminating				your traffic experiences will be twice that quoted by
the need for the hardware involved in multiple				your service provider.
networks. With fewer systems to purchase and house				Video
at additional sites, you can save on the capital cost of				'Real time, two-way' Video over IP such as video
servers and related equipment. This has a knock-on				conferencing applications requires low latency,
effect of reducing software licensing fees and support				whereas streaming video or Closed Circuit Television
costs.				(CCTV) does not place such high requirements on the
Facilities management				packet delivery system.
Centralising your network also simplifies its				Data
management, monitoring and back-up and streamlines				Data back-up and restoration necessitates low packet
the administration of software licensing, generating				loss. A good rule of thumb is that the lower the latency
further cost savings. Before Metro and National				and jitter figures cited by a provider, the better their
Ethernet services became widely available, companies				service will be. It also pays to consider whether a
had two main options for their network management.				provider can support 'any-to-any' connectivity between
They could either allocate networking staff to manage				your sites.
the main servers on the network at every physical				Performance of existing applications
location, or centralise resources and connect them via				If you intend to consolidate your servers into just one
ATM or Frame Relay %u2013 both of which were				or two nationwide locations, then you need to bear in
expensive.				mind that established applications may be designed to
This also resulted in many companies under-utilising				operate over a network with LAN levels of
their capital equipment by being forced to duplicate				performance, where jitter and latency would be very
resources across multiple sites, often implementing				low.
upgrade programmes before some sites became truly				To get a clear indication of a provider's network
obsolete and failing to optimise the skills and availability				performance, review their SLAs and be wary of those
of their staff across the entire network.				who do not include target levels for performance. This
An Ethernet-based network also gives you flexibility in				is often an indication that they over-provision or
where you centralise your network management.				contend their core networks, which will inevitably
Rather than recruiting and locating staff in				jeopardise the performance of your network.
headquarters, for example, you can instead choose to				Ethernet Latency
move network management to a regional office,				The time taken for traffic to travel from one end user
where staff skills are cheaper to acquire and property				site, across the inter-site network or link, and reach the
overheads lower. According to Ovum 1 , 70% of the				other side. Some service providers quote "round trip
cost savings from consolidating network resources				delay," which is simply double the latency figure.
comes from such staff and accommodation cost				Latency is measured in milliseconds. VoIP and realtime
reductions.				video are both sensitive to high latency.
Reduced staff costs				Jitter
The overall staff costs of managing a single Ethernet				The latency of a link is not constant: a series of
network are lower than with ATM/Frame				measurements collected from one route will show a
Relay-based networks, because Ethernet skills are				variety of latency times. Jitter is the amount by which
widely available and cheaper to recruit than WAN				this latency varies, i.e. the difference between the
router specialists.				shortest and the longest latency time measured. Jitter
2.2 Increased IT efficiency				is also measured in milliseconds. VoIP is more sensitive
With Ethernet, the integrated LAN can effectively				to jitter than real-time video (as opposed to streaming
extend anywhere, yet be managed centrally. This is				video). However, excessive levels of jitter can
both cost-effective and efficient.				nevertheless disrupt both voice and video.
Simplified management				Packet loss
The WAN can use the same protocol as the LAN,				Also known as packet delivery, a measure of the
making it far easier to manage the two. Companies				percentage of packets that successfully traverse
that have Wide Area or Metro Area Ethernet solutions				theinter-site network. Almost all types of packet, frame
can also manage their LAN and WAN with a common				or cell-based networks lose a small amount of traffic. If
set of management tools %u2013 which in turn				applications are using a higher layer protocol like
removes the need to source and recruit specialist skills				Transmission Control Protocol (TCP) then these lost
in Frame Relay or ATM technologies.				packets can be retransmitted. However, many
Lower maintenance				applications use User Datagram Protocol (UDP), which
Centralising the management of the network also				does not retransmit lost traffic. VoIP, Video over IP or
simplifies system monitoring and back-up, substantially				data backup are examples of applications which use
reducing the level of maintenance needed on the				UDP and can therefore be vulnerable to packet loss.
network.				Choosing a service provider whose network has a
Strategic deployment of IT resources				low packet loss is therefore important.
By reducing maintenance and management issues				4.4 Flexibility to add future services
with an Ethernet-based network, you can reallocate				An inter-site service that is future-proof will be able to
staff that would previously have been required for				support new applications as they are introduced
reactive management and maintenance to IT projects				further down the line. Even if applications such as VoIP
that proactively support business progress.				and multimedia are not current requirements, it is
The optimal network				important for your business to have the flexibility to
With no geographical constraints and less drain on				incorporate these technologies quickly and easily
budgets, you are free to design the ideal network to				should the need arise in the future. Being able to take
exactly match the needs of your business.				advantage of these new technologies without having
2.3 Improved business protection				to reinvest in your inter-site connections is therefore an
Disaster Recovery, the process of regaining access to				important requirement when reviewing providers. A
the data, hardware and software necessary to				future-proof inter-site service also gives you the option
resume critical business operations after a natural or				of agreeing a long-term contract and benefiting from
man-made disruption, often implies preparation for a				term discounts, safe in the knowledge that there will be
freak catastrophic incident. However, very often the				no need for costly upgrades if new applications are
type of events that can affect business continuity are				needed in the future.
much more mundane or routine occurrences, such as				Supporting Virtual Private LAN Services
a power cut, or even simple human error.				Not all Ethernet inter-site services are based on
So it's vital to ensure uninterrupted availability of that				state-of-the-art technology such as MPLS, some are
information in the event of system downtime "for				even based on ATM. Whilst Ethernet presentation of
whatever reason" and to deal swiftly with any issue				ATM services brings some of the benefits delivered
that affects any part of the network and has the				by true switched Ethernet services, it suffers significant
potential to threaten the smooth operation of your				drawbacks.
business.				The fixed size of ATM cells means that small packets
Ensuring business continuity				(e.g. VoIP packets) have to be carried in two ATM
The growing importance of adequate business				cells with most of the second cell being 'padded' out to
continuity measures is being driven by				make it up to the mandatory ATM cell size. The effect
companies%u2019 dependence on IT and by the				of this padding is that throughput on an access circuit
higher expectations of their customers, who demand				can reduce by up to 35%, with a 100Mbps service only
the kind of 24x7 service that can only be delivered by				being able to support 65Mbps of traffic.
the most robust technology.				MPLS-based or true switched Ethernet-based
Historically, putting a business continuity or disaster				services, by contrast, don't suffer from this limitation so
recovery solution in place to protect the business was				there's no need to investigate the packet sizes of your
a complex and expensive task. However, Ethernet				existing network traffic. MPLS-based core networks
now makes it possible to deploy a highly				make it possible to deliver potentially attractive
cost-effective solution by enabling business critical data				services such as Virtual Private LAN Service. VPLS
to be backed up remotely over a high speed network				permits national end-to-end Ethernet (i.e. Layer 2)
between corporate HQs, regional locations and				services to support any-to-any or peer-to-peer traffic,
business continuity sites.				making network management much easier and
For example, over an Ethernet network, it is easy to				enabling new applications to be plugged in as and
mirror corporate databases in real time. If a live				when required at vastly lower cost than in a multipoint
database should go down, an up-to-date back-up copy				network.
is immediately available and easily accessible to any				In the Heavy Reading Survey 2 , 68% of Enterprises
employee over the network, regardless of their				rated VPLS as an important requirement in the future
physical location.				prosperity of their business. Because of its current and
2.4 Greater productivity & customer service				growing future importance, it is worth making sure that
The benefits of Ethernet-based networks can also				the long-haul Ethernet services offered by your
enable you to explore new ways to increase staff				chosen service provider don' have any technology
productivity and levels of customer service to gain a				barriers that prevent them from being able to support
valuable edge over your competitors.				VPLS.
Deliver improved service to customers				4.5 Terms & coverage of Service Level
Over a secure Ethernet connection, you are able to				Agreements
make information much more immediately accessible				Many SLAs only cover part of the service, and very
to staff, no matter where they are located. They can				often exclude the access circuits as they are provided
hold virtual meetings, develop more collaborative				by a local access wholesaler and are therefore
working practices and use electronic whiteboards to				outside the control of the overall inter-site service
share and discuss information.				provider. Look for providers that include all elements of
Training can also be delivered in interactive sessions,				the service, including the access circuits.
independent of location, over the network rather than				Additionally, examine the terms applied by a provider
on costly, time-consuming training days, enabling it to be				to fault resolution. For fault repairs, guarantees are
delivered much more frequently.				usually measured in hours and / or annual availability,
This all results in better informed and better trained				and it is vital to check that the service provider
staff able to provide greater levels of personalised,				considers that the fault has started when either the
immediate service to customers.				customer or the service provider detects the problem.
Deliver new services to customers				4.6 Security
Customers increasingly expect to interact with their				Security is an important concern with any network.
suppliers using the web or multimedia applications. For				Fortunately, most of the technologies that underpin
example, nowadays, most telephony providers, utilities				intersite Ethernet products are generally considered
and banks provide billing and customer service				safe and, where there are risks, they are well
information online. Ethernet's affordable high throughput				understood. None of the inter-site Ethernet products on
of data means that it is well-suited to support such				the market today rely on the internet as the backbone
services by enabling them to be delivered cost				network. However, if any of your sites have an
effectively and quickly over a high quality network.				internet connection, adequate inter-site and internet
Depending upon the nature of their business,				security solutions must be put in place by the service
companies can also look to introduce innovative new				provider. This will typically include firewalls at the
services such as multimedia and interactive				gateway to the internet and access restrictions to
presentations, to enhance how they attract and sell to				different parts of the internal network for different
both customers and prospects.				users, using such methods as Virtual LANS (VLANs).
Deliver new services to employees:				5 Conclusion
VoIP & video				Ethernet-based connectivity for corporate LAN and
Many UK enterprises are adopting Voice over IP				WAN offers broad business benefits. A massive
(VoIP) in a phased manner to take advantage of				growth in spend on Ethernet services by UK
significant call cost savings, easier systems				companies is being fuelled by their recognition that this
management and the new applications that can				mode of transport for IP services gives superior
dramatically improve communication, productivity and				technical performance at a vastly reduced cost than
service levels. However, VoIP makes heavy demands				traditional Frame Relay or ATM technologies. By using
on bandwidth and network resources, and requires low				Ethernet-based connectivity to integrate Wide Area
latency, low packet loss and small voice packets to				and Local Area Networks into a single, national LAN,
perform properly.				you can expect to:
With the ubiquitous high-quality bandwidth capacity				- save costs
delivered by Ethernet, companies can maximise the				Bandwidth, equipment and supporting specialist skills
opportunities presented to them by VoIP capability.				are all far less expensive when compared with Frame
Innovative solutions such as video conferencing to aid				Relay, ATM and other alternatives. Consolidation and
employee training and minimise travel costs, as just				centralised management also minimises hardware
one example, can be deployed with full confidence in				requirements, and reduces capital and software
the robust performance of such applications.				licensing costs
3 Underlying Ethernet technologies				- facilitate network management
There are numerous technologies and connection				With Ethernet, the integrated LAN can effectively
mechanisms that can underpin an Ethernet service.				extend anywhere, yet be managed centrally. This
You need to choose a service based on underlying				makes the network easier to maintain and saves IT
technology that will suit both the IT and commercial				resources that could be deployed more strategically to
needs of your company, not just in the short term, but				support your business
in the future when you may wish to explore new				- protect business continuity
business opportunities.				You can take advantage of the greater speed and
3.1 Short haul & Metro Ethernet				bandwidth of Ethernet connectivity to deploy robust
Point-to-point Ethernet services are based on supplying				disaster recovery measures and ensure staff can
a dedicated fibre pair for each connection, which is				access business-critical information in the event of a
physically laid through the service provider's local hub				major outage or catastrophe, regardless of their
site. No routing takes place; data packets go in one				location
end and come out the other, exactly as they went in.				- flexibly develop their business and services
The advantage of this is that there is no routing				Ethernet connectivity underpins applications like VoIP,
overhead and faster delivery.				multimedia and real-time video to enable you to provide
Multi-site Ethernet services for the metro (regional)				value-added services to customers and staff, such as
area often use switched Ethernet technology and do				online provision of information, collaborative working
not usually touch a core network. This delivers better				and distance learning.
performance than a service that traverses a				Checklist for sourcing an Ethernet service provider
provider's core network. However, metro-based				Identify cable companies with fibre, not copper-based
services are restricted to the regional area, and				coverage, that have good local presence and an
generally the benefits of long haul connections will				extensive national core network to enable them to
outweigh any loss of throughput over longer distances.				provide a combination of both short and long-haul
The ideal provider is one with good local presence and				Ethernet services. A large number of PoPs will also
an extensive national core network, which can provide				enable the provider to offer you the best-priced
a combination of both short and long haul Ethernet				solution. Seek evidence that the provider does not
services.				over-provision capacity, which will degrade the
3.2 Long haul Ethernet				performance of your network, but instead offers
3.2.1 General				end-to-end Ethernet services. Look also for providers
In the case of long haul or National Ethernet, a portion				that publish and include target levels for network
of the service is usually carried over some form of				availability within their SLAs. Check the terms on which
core network. Multi Protocol Label Switching (MPLS) is				support services such as fault resolution are delivered,
widely accepted as the best type of core network for				to guarantee the level of service you are paying for.
supporting both legacy and future applications. This is				Choose a provider that can provide the requisite
partly because many service providers plan to offer				security applications and measures to safeguard your
the highly attractive Virtual Private LAN Services				network from attack and potentially crippling outages.
(VPLS) over their MPLS core network.				Look for the flexibility to introduce new applications
3.2.2 MPLS				quickly, easily and cost-effectively onto your network
MPLS provides the ability to define and support				in the future without the need to exit expensive,
different classes of service to individual flows of				constraining contracts or undergo costly or disruptive
traffic, prioritising bandwidth and enabling you to make				upgrades. 1 Ethernet in the WAN, Cause and Effect,
the most efficient use of your capacity to ensure				Ovum.
carrier class delivery without increased cost.				2 2004 Survey of Ethernet Service Providers, Heavy
3.2.3 Virtual Private LAN Services				Reading.

ITIL

Choosing Your Ethernet Service Provider