Service providers require a scalable, resilient, manageable IP PBX telephony function that will provide a high level of PBX features to their managed services customers.
A backbone VoIP transit switch function is also needed to provide centralized, unified dial plan management and an interconnect to the PSTN using both PRI and SS7. The scalability required for most service providers is at least 100,000 total telephone endpoints.
One key requirement is for the division of the dial plan, administration and control into logical customer or tenant areas, to allow providers to effectively offer service to their separate customers from a common call control platform in a secure and manageable way.
There is obviously also a requirement to bill for calls between customers and to the PSTN. It is therefore essential that the call control platform provides accurate billing information for these call types.
SIP, as a telephone control protocol, is a requirement to allow the integration of third party phones and to manage advanced features. Proprietary protocols will still be required for extended telephony features.
Automating network and device configuration and service activations (provisioning) becomes an important requirement for converged IP networks. For typical service provider systems there are often hundreds of thousands of provisioning activities across voice network per year, so there is a requirement to automate these processes.
Providing advanced UC applications on a hosted, multi-tenant basis adds to the requirement for automation. For example, adding what might appear to be a simple voicemail service requires configuration not only of the Voicemail platform, but also of the transit soft-switch for call routing of diverted calls, as well as the IP-PBX for message waiting indication. Each additional voicemail account may require up to 10 transactions across the platform. When multiple applications are involved, the number of transactions increases by orders of magnitude.
In most cases it is not sufficient to treat all users, phones and services as a single mass of data when implementing automation. Data needs to be segmented within provisioning and activation systems to allow different groups of users and equipment to be managed separately. Typically, there is a requirement for multiple levels of management, with the highest level administrators able to access all data and perform all functions, but lower level administrators only able to access specific data relative to their rank and to only be allowed to perform limited tasks.
For service providers supporting multiple tenants on the one network, provisioning systems must allow individual customers secure access to make certain configuration changes to the phones allocated to that customer without having access to other customer’s phone configurations.
The ability for customers to provisions and change the configuration of their own allocated equipment drives a requirement for the Provider to be able to retrieve inventory reports from the provisioning system to allow them to keep track of what resources a particular customer is actually using.
In addition, automation of the deployment process is a key requirement. The cost of deploying large scale IP voice systems across tens of thousands of phones is a major contributor to the overall investment required by companies.