Q&A Tackles Server Requirements, Disaster Recovery
More Nortel Migration Paths:
6-Vendor Comparison of Layering Options 

Feb. 11, 2010 (Vol. 31, No. 3)

Avaya’s Aura has gotten a lot of press as one migration path for Nortel users after Avaya bought the Enterprise Solutions division of the bankrupt communication systems maker in an auction last September.

Avaya encourages customers to add Aura “on top” of their existing PBX environments for enhanced collaboration capabilities. Eventually, some functionality from Nortel’s products will be merged into Aura, which provides multi-vendor integration [VR 1/28/10].

Aura uses a SIP session manager to centralize communications and applications integration in networks that use PBXs from multiple manufacturers. Avaya pitches Aura as a cost saver, enabling enterprises to keep existing equipment in place and eliminate PSTN access charges [VR 4/9/09].

But Nortel users are committed to doing their due diligence when it comes to upgrading from legacy gear; other vendors provide this type of “layering” technology, too. Layering technology adds a “layer” for trunking, trunk routing and other applications to be implemented by a central layering server. These solutions add features like centralized SIP trunking, single dialing plan, reduced costs through trunk optimization and the ability to add centralized voice mail and unified communications. 

All of this can be added for a multi-site enterprise without changing out existing PBX systems or telephone end points. So layering technology can help your enterprise migrate from a legacy system (made by Nortel or any other manufacturer) to VoIP and UC without replacing what’s already installed. Some capital will be required for layering, but most investments have an ROI of less than 18 months after deployment. 

Depending on what PBX equipment is in place, gateways are commonly implemented at edge sites to connect sites seamlessly. Note: The layering technology can be used in a multi-manufacturer environment.

Voice Report Contributing Writer Stephen Leaden, president of independent telecom consulting firm Leaden Associates Inc., surveyed six vendors to compile a comparison that you can use to jumpstart your evaluation next time you’re in the market.

Read on for answers from Aastra, Avaya, Interactive Intelligence, Mitel, NEC and Siemens Enterprise Communications, each of which provides layering solutions that integrate with Nortel. The responses have been edited for grammar and length. Cisco did not respond to requests for comment.

What Level of Integration and Seamlessness Have You Achieved?

Aastra: Aastra’s standards-based integration exists in the corporate cloud. It keeps and enhances existing equipment. It’s available to all users and is not equipment dependent. It provides support for direct SIP trunks to third-party PBXs to backhaul calls and provide a common routing point. TDM systems will require a gateway. It includes carrier-class support and load balancing.

Avaya: Avaya “Session Manager” centralizes communication control and application integration and provides enterprise-wide SIP architecture among all enterprise sites. Session Manager contains “SIP adaption modules” for different systems and service providers that normalizes and converts SIP headers to ensure better transparency between systems.

Interactive Intelligence: I3’s integration exists at many levels and is very flexible to adjust to the needs of each deployment. Voice integrations can be done via SIP and IP, TDM, trunks or via tie lines.

Mitel: Mitel uses a signaling proxy technology adopting an IMS model. Mitel also uses a Mobile Dynamic Extension model. This allows third-party phones to be treated the same as proprietary phones.

NEC: It depends on the specific Nortel product. NEC supports SIP, redirect, native proxy (E2.V) either direct or through a gateway.

Siemens: OpenXchange has been in Siemens’ portfolio for more than three years. It is based on carrier heritage of the OS voice platform used as a class 4 tandem switch and media gateway controller, with SIP-based call control; enterprise-level feature sets; Linux operation systems; and APIs to enterprise management, applications and provisioning. OpenXchange typically starts in the data center or from a service provider.

What Features and Functionality Do You Provide?
 
Aastra, Avaya, Interactive Intelligence, Mitel, NEC and Siemens Enterprise Communications provide single dialing plans and smart call routing (including trunk optimization and SIP) with their layering solutions.

Aastra, Avaya and Mitel support audio conferencing. NEC provides audio conferencing along with desktop videoconferencing, and Siemens clarified that it can deliver audio conferencing as a standalone function or as part of a UC implementation. Interactive Intelligence did not respond to this question.

Can You Integrate with Voicemail? Unified Messaging? UC?

Each of the six vendors surveyed supports voicemail and unified messaging integrations with its layering products.

Aastra, Avaya, NEC and Siemens support integration with unified communications, to provide features like IM/chat, presence, soft phone, audio conferencing, videoconferencing and Web collaboration. Interactive Intelligence says its video and IM functionality is supported through Microsoft OCS. Mitel can integrate UC with its layering solution, and also offers a competitive product to OCS.

What Protocols are Used?

Aastra: SIP, RTP and Secure

Avaya: H.323, H.248, SIP-ISC, Q.SIG/SIP, XMPP and SIP/SIMPLE, TDM protocols

Interactive Intelligence: SIP; other protocols are supported by using a gateway or other device to transcode

Mitel: QSIG and QSIG extensions

NEC: SIP and H.248 are the primary protocols used

Siemens: SIP is the primary protocol; MGCP is used for media server control, SOAPXML and CSTA are also used extensively in the platform

What is Your Projected ROI for the Layering Technology?

Aastra: 12 to 18 months for an entire system typically

Avaya: Fewer than 12 to 18 months projected, often one particular add-on application with a similarly rapid ROI

Interactive Intelligence: Most I3 customers realize an ROI within six to 18 months

Mitel: Typically six to 18 months depending on configuration

NEC: Typically 12 to 24 months depending on configuration

Siemens: The projected ROI has ranged from eight to 16 months depending on the applications deployed and current solutions

How Many Servers are Required for the Above Applications?

Aastra: Minimum of two servers

Avaya: Two or more Avaya S8800 Linux servers deployed geo-redundantly. Other applications then require their own servers, which may also be redundant and duplicated for scale – for example for Communication Manager, Presence Services, Meeting Exchange, etc.

Interactive Intelligence: Depends on configuration, but usually one primary server and optionally one redundant server

Mitel: Single server to several, depending on configuration and level of redundancy desired; managed through Mitel Applications Suite

NEC: Typically 3 maximum

Siemens: Physical servers are dependent on number of supported sessions and subscribers. OS voice is generally deployed as a dual-node clustered pair and can support as many as 100,000 subscribers, with application functions as many as 60,000 subscribers.

Where Would the Servers Reside in a Multi-Site Network?

Aastra: At key corporate site or in the cloud

Avaya: At key corporate site or in the cloud

Interactive Intelligence: Anywhere voice and data can be delivered with sufficient bandwidth. Possible configurations range from one central server to individual servers at each location

Mitel: They would typically reside at client primary and secondary sites

NEC: At customer sites or at a cloud site

Siemens: Depends on client configuration; can reside at primary sites, secondary sites or in the cloud.

What is the General Design for Disaster Recovery?
Multiple Servers in More than One Location?

Aastra: Yes, can cluster two or more servers together across multiple sites and be completely redundant

Avaya: Yes, can cluster two or more servers together across multiple sites and be completely redundant

Interactive Intelligence: Multiple hot redundant servers in primary location plus hot redundant server offsite

Mitel: Yes, multiple servers can reside at multiple sites with failover capability. There is no geographic site dependence.

NEC: The NEC system is very relievable and can easily support one or multiple disaster recovery methodologies. It can be deployed with system hardware redundancy, providing greater than 99.999% system uptime. This eliminates the issues with phones needing to re-register and losing calls during failover. It can also support automatic failover, and/or automatic recovery.

Siemens: OpenXchange works on the principle of an active/active architecture, with each of the two nodes supporting full hardware/software redundancy down to the network interface card level. All call contexts are replicated bi-directionally between each node such that a single node in the cluster can take over and support all users in the network without loss of functionality

Is the Layering Technology Targeted
as a Cloud Computing Replacement Model
(If Desired by the Enterprise)?

Aastra: Yes, and it provides enhanced experience via multi-tenant and carrier class platform. Support for Avaya SIP phones, trunk aggregation, SIP session monitoring, call accounting and centralized unified messaging are part of the baseline product portfolio.

Avaya: Aura provides the elimination of local application servers, which in turn optimizes software licensing across the enterprise rather than for a single location. The Aura model can be used at the enterprise level or in the cloud. Avaya is replacing the classical “location-based” PBX and IP PBX architecture (incrementally) with a new enterprise-wide SIP-based real-time communications architecture.

Interactive Intelligence: Customers can choose premise-based or “communications as a service” (CaaS) deployments. CaaS offers a fully hosted system or a unique Local Control VoIP model that keeps data and voice on the customer’s local network (enhanced security for sensitive industries) with SIP signaling and advanced contact center functionality provided by the hosted CaaS system.

Mitel: Mitel is currently partnering with VMware for cloud-based modeling utilizing a private cloud environment.

NEC: Yes, one of the system’s primary design parameters was to meet the needs and requirements for customers looking for the cloud computing model.

Siemens: Siemens has launched its cloud prototype in the Amazon EC-2 cloud. This involved porting our entire architecture into Amazon’s cloud as well as building a front-end portal as a single entry point for enterprises to order, provision and manage their environments without taking on the capital expense burden.

Other Comments

Aastra: Aastra’s Clearspan utilizes open standards, an all-SIP UC platform and provides centralized architecture that can be remotely managed. It is built around a five-nines reliability model and offers a full suite of presence integration, FMC, conferencing and contact center features. It supports as many as 20,000 end points per session manager instance.

Avaya: Aura includes Communications Manager (pushes SIP integration to Avaya’s Business Feature Server), Presence server and Application Enablement Services, which provide unified communications to Microsoft OCS 2007 R2 and Lotus Sametime 8. Aura also maps applications to individual employee profiles, regardless of location or device to which they are connected. Aura provides better call control among multiple call centers and sites. The Aura product scales well at as many as 250,000 business users and 25,000 locations.

The core integration of Nortel Enterprise systems with Avaya Aura Session Manager is through SIP (trunking). Avaya has certified CS 1000 R5.5 and later, and CS 2100 SE13 with SIP.

SIP (trunk)-based applications connected to Session Manager can be delivered to users on any kind of phone connected to any system that SIP-connects to Avaya Aura (so including all of the above Nortel Enterprise systems). This includes Meeting Exchange (conferencing), Modular Messaging (centralized unified messaging), Voice Portal (customer announcements and self-service), Intelligent Customer Routing (routing from Voice Portal to the right contact center with in-queue self-service handling until agent availability).

Interactive Intelligence: Voice integrations can be done via SIP and IP, TDM, trunks, or via tie lines – essentially any standard means of passing voice in or out of another system. In I3’s CIC platform, there are multiple methods to route calls to an extension on another platform or receive a call from another platform. Integration with databases, CRMs and some third-party applications like Siebel and SAP is provided through built-in connectivity within CIC or packaged integrations

Mitel: Dynamic Extension does not require a Mitel phone and can include as many as eight phones of any description to be included under a single number. Mitel Communication Director’s (MCD) call control adds new capabilities to the third-party solution: twinning with mobile phones, soft clients, teleworker and presence. Basic calling-line ID and DID support on the third-party PBX allows for significant integration of Mitel features that can be enhanced if the third-party PBX supports advanced capabilities such as SIP trunks.

NEC: NEC can provide a soft or gateway model depending on customer requirements.

Siemens: Beyond the single dialing plan, OpenXchange is able to manage complex dial plans that most enterprises have implemented over time through growth or acquisitions. OpenXchange supports time-of-day routing, free media choice, ENUM services, centralized trunking services, tail-end hop-off, E911, as well as CALEA services natively. Siemens can also integrate with all major LOB applications such as SAP, salesforce.com, Microsoft and IBM software suites. Through the UC client, Siemens can provide one-number service, device integration, granular calling rules, QOS management and CDR functions. (

Stephen Leaden is president of Leaden Associates Inc., an independent telecommunications and IT consulting firm in business 19 years. He is also a principal with TelecomUCTraining.com, which provides independent telecom training. Steve is past president of the Society of Telecommunications Consultants, a national association that requires ethics and objectivity as a prerequisite for membership. Steve can be reached at 845-496-6677 or sleaden@leaden.com. View Leaden’s webcast on the Avaya/Nortel roadmap at www.thevoicereport.com/AvayaNortelRoadmap.