Convergence Deep Dive - Part I

Elements of Convergence
The Migration
Shades of Convergence
Benefits of Convergence
WAN Convergence
LAN Convergence
Part II

Elements of Convergence

Today's buyers of enterprise telecommunications services are an increasingly business- savvy group. In addition to looking for the most efficient network solutions from a purely technical perspective, they continue to be focused on deploying services that mirror their organization's business goals.

Solutions that include elements of streamlining total cost of ownership coupled with internal/external business productivity requirements, for example, are quickly becoming the standard-bearer for how enterprises engage telecommunications service providers.

Global Crossing believes that for enterprises to align their universe of business goals with productive and cost-effective communications, it is necessary to implement a single communications infrastructure that is capable of supporting the transmission of voice, video and data communications over a single physical connection - a converged network communications environment.

By many estimates, global enterprises have begun planning for to converge their voice video and data services over a single connection themselves -- or are spending time to understand the business benefits of a successful implementation.

This paper is meant to provide you with a big-picture, end-to-end perspective on convergence -- recognizing that there is more to it than integrating your data and voice services over a wide area network (WAN).

In fact, as perhaps many global enterprises are discovering, a well-defined enterprise convergence strategy touches upon many aspects of your business, beyond the communications network and infrastructure - human resources, systems, and processes that are required to support it. Also important is how a service provider can help you across all many of the end-to-end dimensions of convergence above and beyond WAN services.

The Migration

Convergence should be viewed as the next logical step on the way toward creating scalable, adaptable network infrastructure that can be changed as business needs require. With convergence still in a prescient stage, it should be viewed as roadmap that recognizes that the pace of network evolution that can vary greatly by company and some companies may leap-frog an entire stage along the way.

The vast majority of global enterprises today are migrating to MPLS-based Network IP VPNs. There are number of reasons for this. First, the key point to make is that for many global enterprises, an MPLS-based IP VPN has become the foundation, or starting point for facilitating the evolution to Convergence. And second, that an enterprise is not required to be running multi-service data, voice, video applications to take advantage of that an IP VPN offers. True, an IP VPN provides a powerful platform for stand-alone data-only applications. But if you are thinking about converging your networks and services, it becomes a migration point upon which you build your convergence plans.

Of course there are other ways to construct virtual private networks. VPNs can be constructed from connections using frame relay, ATM, even private-line. There are, however, substantial benefits to using MPLS-based IP VPNs:

• Improved performance - delivered through integrated QoS and RSVP-TE (traffic engineered network); reduced overhead versus ATM based QoS; hop-count reduction and less delay because the routers switch through the core at Layer 2 and do not need to make Layer 3 routing decisions as is the case with traditional IP routed networks.
• Scalability - in terms of bandwidth support (frame relay maxes out at DS3/E3 ) and inherent any-to-any full-mesh connectivity.
• Built-in reliability - inherent ability of IP to automatically "route" around a failure versus use of dedicated virtual circuit re-routes in Frame/ATM.
• Provisioning - you do not need to provision separate PVCs for connectivity thereby reducing complexity and overhead and simplifying the need to support user configuration-change requests.
• Built in security - The use of VPN labels create a "logical virtual circuit" capability - similar to a Frame Relay or ATM virtual circuit - to ensure customer traffic is separate and private from other customer traffic in the network.
• Widely adopted standards that the entire industry uses.
• Enabling technology for converged IP services.

Shades of Convergence

There is no universally acceptable definition of convergence. An enterprise should choose infrastructure and applications based on business need and where they want to be in terms of the evolution path as discussed previously.

For purposed of this discussion, here is a good working definition: convergence is communications infrastructure that applies to your local area network (LAN), WAN, network applications and operations infrastructure, which includes your support personnel, systems, and processes. The operations component actually encompasses and surrounds the other three (LAN, WAN and network applications).

Although each element poses its own different set of considerations and challenges and adoption levels might be different, ultimately an enterprise will need to converge across the aforementioned elements in order to derive the full benefits of convergence.

Benefits of Convergence

As stated previously, the benefits of convergence greatly depend on enterprise business needs. There are, however, what can be described as universal benefits, which include the following:

Cost Savings
Largely driven through network consolidation which drives a lower total operational cost:

• Access consolidation - multiple services onto a single access and connection and transport over a single network infrastructure. This enables an enterprise to save money by 1) eliminating separate networks and access (example, a separate dedicated IP Video network and dedicated ISDN access connections for video conferencing). 2) minimizing the amount of access and network bandwidth you need based on the efficiency of IP - example VoIP compression of up to 8 to 1 (8 kbps per call versus 64 kbps per call).
• In the LAN - consolidation of services on to a converged, streamlined IP LAN environment. Consolidation of stand-alone legacy systems - PBXs, phones, video equipment, and desktops onto a single, consolidated, scalable IP LAN infrastructure. Less systems, less human capital, less maintenance and software charges, less support.
• In Operations - streamlining systems and process into a single IP based operational model and support system and processes. A common operational model also enables greater efficiency in staff productivity and quality.

Applications
Leveraging IP as the basis for new, powerful applications, both Internet-based applications and corporate network applications. There are direct cost savings for each when compared to legacy applications (VoIP, IP Video) and there are business benefits from such productivity improvements, ubiquitous availability, speed at which new applications can be implemented within the corporate network. Just think how long it used to take to have your analog phone number moved to a new office. With VoIP, an IP Phone move/add/change is real-time plug and play.

Ubiquitous Transport
Again based on IP - Internet. Your enterprise business network. Wireline. Wireless. IP is quickly becoming the basis of corporate communicating today.

WAN Convergence

Making the right WAN choice is critical to ensure that you can benefit from a converged IP environment, both short term for the future. Of course choice of service provider is instrumental, and here enterprises have the option of relying on service provider capabilities for assisting with their convergence plan.

What defines a convergence-ready service provider? Here are some key considerations to think about in terms of the WAN:

• Performance - will you get the quality and reliability of service you need to support your business, network application needs? Critical here are 999.99% availability and a customer support team that treats each enterprise as though it were its only customer.
• Security - a service provider that can deliver the safeguards to protect enterprise confidential traffic across their WAN, meet your security requirements for connecting your remote and mobile workforce and manage to the demarcation perimeter the enterprise defines.
• Experience - a service provider has the know-how to deliver the systems and processes needed to support your end-to-end service. A good provider will lift the burden of convergence complexity and providing the service visibility and control an enterprise needs.
• Evolution - a WAN with advanced network technology and IP capabilities that is fully interoperable with previous technologies so that allow an enterprise to migrate over time and at its own pace.

LAN Convergence

Lets take a look a similar set of challenges and considerations in the LAN.

Infrastructure
With so much capital invested in a LAN infrastructure, an enterprise wants to squeeze every last penny out of it before deciding to replace it. This can affect your convergence timing. And when the decision is finally made, an effort should be made to ensure that it continues to support legacy applications as well as the new ones.

QoS
Real time applications require that an enterprise have the appropriate QoS classifications and the policies in place to control them. By policy, we refer to a network policy that enables you to identify a particular application, classify it according to performance needs, and then ensure your LAN equipment is configured to act properly on the policy you've defined. For example, IP Video creates a stream of very heavy packet frames sensitive to congestion, which results in a slowdown of the video and audio stream.

Problem Management
When everything is an IP packet and converged over a single connection, how do you fault isolate a problem or application and resolve it? You'll need a new set of processes and tools in place to support this.

Administration
Development of new IP-based dial plans for voice-over-IP (VoIP), and assigning responsibility for each application because it's all packet-oriented now. Infrastructure choice also impacts trouble management and administration, for example, a TDM PBX was traditionally managed by a single team with clear lines of responsibility. Within a VoIP deployment, however, IP PBXs are managed by an IP network team.

Depending on your environment, LAN convergence may represent the biggest challenge to an enterprise organization and may require some significant change and re-engineering across multiple areas including those listed here.

Equipment and Software
Your enterprise may need to upgrade to the latest software and hardware releases - for example, router firmware and configuration -- or you may need to purchase brand new hardware and software. For example: will you upgrade your router to act as a VoIP gateway and keep your legacy PBX and phones? Or, upgrade your existing PBX for VoIP by adding an IP card and keeping your existing phones? Or replace your PBX and existing phones completely with an IP-PBX and IP Phones? What release/revision do your routers need to be? Do they have the performance needed to support your new network applications? Should you use SIP or H.323?

QoS and Network Configuration
You will need to define and engineer QoS policy for your network applications and configure desktops, routers, and other LAN devices to support QoS policy. For example Is your router going to recognize QoS priority based on the source IP address of the traffic or will it expect to see the QoS priority (diffserv priority) set in the IP header directly? Or a combination of both?

Numbering
You will need to create a new numbering and dial plan for VoIP and design it into your entire corporate network being careful to address issues such as future scalability, networking/translation between legacy addresses (non-IP phones) and new IP addresses, reach-ability and redundancy/backup.

Bandwidth and Traffic Engineering
Converging your LAN will likely require a complete re-assessment and re-engineering of your LAN and Access bandwidth (with similar implications to the WAN.) For example: How much bandwidth will an VoIP call use (depends on the codec you use). Same for IP Video calls. How much access bandwidth do you need to support peak calling times combined with heavy data application usage times? Have you engineered your IP PBX to support call admission control (accept a maximum of 30 calls and route excess calls to the PSTN?) Likewise have you engineered the PBX and/or router to monitor real-time traffic performance (delay, jitter) and divert calls to the PSTN if performance falls below an acceptable range for VoIP?

Convergence Deep Dive Part II