Conceptual Modeling

In our view conceptual modeling is related to the project starting phase. After kickoff, assessments are carried out and a detailed solution architecture is developed. On demand more detailed functional and technical specifications are worked out and implementation procedures are defined. Although conceptual modeling is highly dependent on the type of project, we have identified some cornerstones

Product Assessment
If no product decision has been taken or too little is known about one or more components, these study may complete the picture by critically reviewing

• Availability
• Cost
• Reliability
• Performance
• Functionality
• Usability
  (by mapping existing requirements
  to products, a usability matrix may be derived)

The result may be either presented in a report or incorporated into specification documents or a technical proposal.

Solution Assessment
Based on existing requirements, technical specifications and product knowledge, a detailed solution concept is worked out covering technical and operational, reliability and performance aspects. The results are presented during a solution meeting to allow for a common state of knowledge among all participants. On demand, an investment protection plan or a rentability & feasibility study may be carried out.

Capacity Planning
By deploying latest queueing theory algorithms and simulation techniques, capacities in terms of trunks, agents, CPU load and other resources are determined. By rating each item with cost, an optimal capacity allocation plan may be derived.

Reliability Planning
Utilizing common reliability theory and latest Markov modeling approaches, reliability interactions in single systems or networks are examined. Various scenarios may be tested for reliability requirements. The results are either presented in a separate reliability report or combined with capacity planning.

Voice over IP Assessment
As VoIP technology is highly dependent on network infrastructure, an assessment is highly recommended. The existing network topology is reviewed in terms of performance and reliability. By deploying latest algorithms in bandwidth and jitter estimation, a set of suggestions and recommendations will be derived. In cooperation with our partner and / or customer, we are then able to derive an optimal solution with balanced price / performance ratio. The following list provides a non-exhaustive overview of the items to be examined

• review of the existing topology (e.g. cabling)
• selection of the appropriate codec preference set and their impact on the network
• impact of signaling traffic (e.g. RTP, RTCP) on the network
• impact of the network topology (e.g. network segments, firewalls) on VoIP traffic
• configuration of switches and routers
• review of measurements (if available)
• configuration of DHCP, DNS, TFTP and other IP services (some vendors rely on existing network infrastructure to run their systems)
• review of quality of service mechanisms (DiffServ, RSVP, MPLS)
• WAN coverage (if required)
• PSTN interfaces (e.g. ISDN, SS7)

We strongly recommend a detailed definition of the targets to be met and the tasks to be performed during a VoIP assessment to prevent from time and cost explosion. As an option customer engineers may be trained for Voice over IP within their environment.

Depending on the project, these and further assessments not described here provide a solid base for the derivation of a conceptual model tailored to customer requirements. As an option, various assessments may be combined with customer oriented trainings. In our experience, such a combination has proven successfully, as it allows for a significant gain in understanding.