Twenty Questions to Ask Suppliers about Voice over IP

By |2022-04-22T22:27:56+00:00May 8th, 2019|0 Comments

Businesses of all sizes today use voice over IP (VoIP) technology for their phone systems. The use of data networks for transporting voice communications has grown dramatically over the past 20 years. VoIP leverages the convergence of multiple application data streams and has proven its value for IT managers who handle voice communications. However, not everyone has embraced the technology, and if your organization is one of the holdouts, this article provides useful planning guidance. 

Following are questions and issues that should be addressed with vendors and network service providers before formally contracting with one or more vendors for VoIP technology and network service.

1. How do the network and terminal equipment handle congestion?
When a network node experiences a “rush” of data packets organized into what are called frames, throughput – particularly as applicable to voice communications – could be slowed, packets could be lost, and overall performance can suffer.  Consider redesigning the overall network to more efficiently handle high-traffic periods. Add flow control measures into the network to control congestion.

2. Are network devices (e.g., routers, switches, gateways) compatible?
VoIP standards are well established and in widespread use worldwide.  Despite this, it’s possible Vendor A’s equipment may not be totally compatible with products from Vendor B.  To ensure that each provides product compatibility use service level agreements. 

3. Do long distance and local network operator networks support IP switching?
Due to widespread use of VoIP technology, and the fact that most local and long distance carriers support the technology, IP network resources may be provided by more than one carrier.  Make sure that each carrier can demonstrate (and guarantee) compatibility with other carriers.

4. How will network monitoring and maintenance be handled?
The nature of networks that support VoIP technology is such that regular performance monitoring and measurement are essential elements of the overall network strategy. Numerous products and services are available to address these issues.

5. How will lost data packets be handled?
No network is infallible, and as such occasionally a hiccup may cause data packets to be lost or dropped.  Consider two options for this occurrence: 1) software in the network access equipment or 2) a resident feature in the carrier’s network. Check availability and compare pricing for each. 

6. What happens if network synchronization is lost?
Data networks depend on synchronization with a clocking source to function properly.  Loss of clocking can disrupt a network.  Ask the carrier/vendor how they will ensure clocking sources are maintained. 

7. Will the network management system support VoIP and other protocols?
Assuming one of the many available network management systems is used, check to make sure the device supports H.323 and related VoIP standards.

8. Have the right applications been selected for converged networks?
Is the focus on voice applications only, or on a true multimedia (e.g., voice, data, video) environment? 

9. Have real traffic volumes been accurately predicted?
Today’s carrier data networks can handle periodic bursts of traffic, but might experience difficulties in extremely heavy traffic situations. Make sure potential network traffic volumes are properly assessed and factored into the network design. 

10. Are pricing elements for VoIP and other network services understood?
VoIP is well established, so when researching and comparing prospective service providers, look for a common denominator (e.g., kilopackets) so that the services can be properly compared.

11. How prepared are vendors and carriers to deliver IP solutions?
Even though VoIP technology has proven itself over the years, planners should ask themselves (and vendors): How can we get the best value for money by using these technologies? 

12. How well do IP-based networks coexist with more traditional networks?
The Internet is a key component of VoIP technology, and even though a firm may be using the Internet for its data traffic, it may still be reluctant to make the move to VoIP. And while today’s voice networks are also Internet-based it may not make fiscal sense to migrate voice traffic onto data networks just yet.  Do the homework to see if you can make the transition.  

13. How will quality of service be ensured on an ongoing basis?
Quality of service (QoS) is an important performance metric for VoIP.  Make sure prospective vendors and carriers can provide you with measurable QoS data, as well as support for VoIP standards.

14. How will VoIP service be billed?
As part of the vendor/carrier evaluation process, compare how they render bills for network service, ensuring that sufficient performance data is provided in bills as well as in separate reports so you can evaluate your network’s performance and value for money.  

15. What network disaster recovery plans are provided by major network service providers?
Most network carriers provide diverse routing, redundant network nodal components, and redundant processing elements as part of their disaster recovery plans.  Prospective users should determine how their operators plan to reestablish network integrity/interoperability if a major cable is destroyed, a power failure disables a switching node, a software failure disables network communications, or human error accidentally disrupts service.

16. How will local carriers support VoIP technologies in a disaster?
Loss of local access lines connecting to a user’s Internet service provider(s) (ISPs) or other wide area network (WAN) carriers could disrupt the network.  Check out emergency recovery and restoration assets from carriers, in addition to route diversity, central office backup power systems, etc.  Use service level agreements (SLAs) to ensure that users and VoIP providers have a clear understanding of the expectations for network performance in a disaster.

17. How will equipment suppliers support VoIP in a disaster?
Equipment failure, poor performance, or other problems could disable a VoIP infrastructure. Find out the emergency provisions available from equipment vendors, in addition to backup units, quick-ship arrangements, and backup power systems.  Again, service level agreements should be used to ensure that emergency arrangements are in place to keep VoIP resources operational.

18. How secure are the proposed carrier network services?
With the increased focus on cybersecurity and protection against cyber threats, find out the security measures available from vendors and carriers to minimize the damage from cyber threats and operational vulnerabilities.

19. Can today’s data networks adapt to evolutionary changes, e.g., as part of a firm’s three-year network strategic plan?
Despite the vast increases in network data speeds and throughput, be sure to engineer your VoIP network to be scalable and adaptable to your current and longer-term requirements.

20. What happens if carriers or equipment vendors change the technology they support?
Or what if the vendor/carrier goes out of business or is acquired?  Make sure you verify that vendors and carriers support VoIP standards and are committed to supporting their products.

Successful implementation of VoIP technology means that IT/telecom professionals must understand the nuances of data networks more than ever.  When planning to implement VoIP be sure to focus on key issues including flexibility, scalability, security, standards, recoverability and survivability, in addition to delivering value to the business. 

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About the Author:

Paul Kirvan, FBCI, CISA, is an independent business resilience consultant, IT auditor, technical writer and project manager with over 25 years of experience.  Previously Mr. Kirvan was a founding board member and secretary of the Business Continuity Institute’s USA Chapter, and a member of the international board of the BCI. Mr. Kirvan is currently a Fellow of the Business Continuity Institute (FBCI) and a Certified Information Systems Auditor (CISA).
Email: [email protected]