Whether you are simply performing a voice-over-IP refresh or getting ready for a complete redesign, it's best to have a plan for what technology you have in place and what you want to accomplish.
Enterprises have many infrastructure considerations to take into account when planning to implement VoIP. New telecom service provider and cloud-based VoIP platforms and services are providing IT departments with more choices in terms of architecture, infrastructure, integration and end-user options.
When looking at the overall picture, put careful thought into public switched telephone network (PSTN) access, LAN and WAN preparedness, end-user connectivity and integration needs. Let's look at all of the options.
Addressing access to the PSTN
When it comes to enterprise VoIP, you need to handle two different types of calls: on premises and off premises. On-premises calling commonly uses three- to five-digit extensions for calls within the same corporate IP-based LAN. If you want to dial outside of the company, off premises, you need to access the PSTN.
For decades, analog and digital plain old telephone service or T-carrier systems were the only options to connect to the PSTN. These technologies use communications protocols other than IP, which is the protocol modern enterprise networks use today. VoIP gateways are required to translate between the legacy telecom network and corporate LAN.
Some telephone companies, however, offer direct Session Initiation Protocol (SIP) trunks that transport voice natively in IP directly to the PSTN carrier. Network administrators no longer have to deal with expensive and complex T1 and T3 line cards in VoIP gateways.
Some enterprise cloud vendors now offer cloud services fully managed by a VoIP service provider. In these situations, off-premises PSTN connectivity can be through traditional SIP trunks or through a SIP connection built across the internet that uses standard broadband internet.
Keep in mind that if you decide to use the internet for PSTN access when you implement VoIP, you lose the ability to control quality of service (QoS). For organizations that consider voice communication a mission-critical service, it's best to stick to legacy analog or digital telecom trunks or IP-based SIP connectivity options. Using the latest internet-based PSTN access means administrators no longer maintain VoIP infrastructure on premises, because it is fully managed by the cloud provider.
Preparing the LAN to implement VoIP
From a LAN perspective, planning for VoIP is all about providing enough end-to-end throughput, while also lowering latency and jitter. Because voice is a real-time streaming protocol, any network congestion can wreak havoc on it. When implementing a new VoIP deployment or a major upgrade, a key step is to audit critical network uplinks across the LAN to identify areas where bottlenecks can occur. If you find links filling up to the point where congestion occurs, upgrading to a faster link or performing port aggregation can eliminate the bottleneck and ensure VoIP traffic is less likely to be interrupted.
Configure end-to-end QoS to make sure the network won't disrupt real-time voice streams. QoS helps further reduce dropped or delayed packets by identifying voice traffic from other types of traffic and prioritizing it so it receives preferential treatment when transmitted from one network device to another.
If you are performing a network upgrade and already have QoS implemented across the network, it's still a good idea to review the QoS configuration, as new and better traffic-shaping techniques may be available to further improve VoIP performance.
Remote-site considerations for VoIP platforms
When it comes to planning to implement VoIP at remote sites, enterprises have plenty of options. WAN connectivity between corporate offices and remote sites is most commonly accomplished by using either leased service-provider MPLS or Metro Ethernet, or through a site-to-site virtual private network tunnel over standard broadband internet connections.
VoIP platform traffic coming back to the corporate office can use either of these connectivity methods. Be aware that whenever you send voice traffic over broadband, you have no way of applying QoS between locations.
Newer SD-WAN technologies can combine multiple internet links with multiple secure tunnels and route VoIP traffic across the link with the lowest detected latency. Many companies are getting rid of their expensive leased WAN options in favor of an SD-WAN-controlled broadband-only setup for their VoIP platforms.
Implement VoIP with the features and integrations
Modern VoIP platforms can offer any number of features and software integration options. One of the most popular features is the ability to have the entire functionality of your office desk phone residing as an app installed on a smartphone. Considering today's growing mobile workforce, this is a very popular feature request by end users.
Looking beyond portability, enterprise-grade applications natively combine voice, video conferencing, text chat and file sharing into a single enterprise team collaboration platform. Most VoIP platforms also offer open APIs to integrate voice with services like trouble ticketing, customer relationship management and AI bots. Combining enterprise apps can enable automation that can streamline business processes.