1. Types of call centers and scalability: How many seats do you have in your call center, and are they based in the same location, or are they spread across different locations? If you are currently using an analog phone service, you may want to start with a small pilot and then gradually increase the number. You can use an analog signal converter to make sure that VoIP phones are able to call analog phones, and also check with your VoIP provider to make sure that external analog-signal phones can call your VoIP-based system.
2. Bandwidth: Check with your ISP to see if it can provide enough bandwidth for the estimated call traffic and account for the cost.
3. Hosted or self-built: This is a major source of cost. On-premises telephony equipment is expensive, and companies have to pay for maintenance and upgrades and train their own technicians to maintain the system. A hosted system, on the other hand, is connected via a high-speed Internet connection, eliminating the need for a PBX service, but it usually requires a gateway and OoS (quality of service) equipment to ensure the quality of the voice. If your company is already using a PBX analog system, you'll want to compare the two and weigh the cost of building your own system.
4. Telephone-based or computer-based service: For modern call centers, a computer-based system may be more convenient. It usually displays call numbers and voice messages on a screen and allows operators to select numbers from a list to call. Some providers can also support online question-and-answer sessions for basic problem-solving via data communications.
5. Architecture: There are two main architectures for VoIP services: H.323 and SIP (Session Initiation Protocol). A number of VoIP vendors currently favor SIP, but these two architectures will continue to coexist and interoperate with each other as technology evolves. Therefore, when you choose a VoIP vendor, the ones that can handle both technologies should be the ones you focus on evaluating.
6. Security: Firewalls, anti-spyware, anti-virus tools, these are all conventional security protection tools. In addition, you can also consider the use of VPN (Virtual Private Network) to secure the network. NAC (Network Access Control) technology can also put a lock on your call center. It provides secure login control and ensures anti-virus and timely Windows updates.