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Managing VoIP in high traffic
Network congestion can make or break your VoIP system.
When your business network can handle high traffic, your VoIP system will work smoothly even during peak network usage.
But if your system is outdated or poorly configured, you’ll notice the effects on your VoIP call quality, frustrating your employees and customers.
This guide explains the symptoms of a VoIP system that cannot handle traffic, how to troubleshoot it, and how to upgrade it to handle your projected business growth.
Contents
- The impact of high traffic on VoIP
- Troubleshooting VoIP traffic issues
- Traffic-resistant VoIP phone systems
- Ensuring a VoIP system that handles high-traffic
The impact of high traffic on VoIP
When a proficient provider sets up and manages your business VoIP phone system, the impact of high traffic is negligible. The broadband connection and internal network supporting it are configured to withstand peak usage and leave ample margin for growth.
However, some businesses exceed their growth forecast or are not on top of network upgrades. In both cases, data and call traffic start exceeding the system’s capacity, causing some network-wide problems that we’ll explain in the next section.
Symptoms of a congested VoIP system
If your VoIP system starts experiencing any of the following issues, it is suffering from congestion due to traffic exceeding capacity.
VoIP quality deteriorates during peak hours
If multiple employees report that their calls are dropping, audio lagging, or conversations echoing, it’s a clear sign of deteriorating VoIP call quality due to high traffic. It’s a sign that your VoIP system isn’t receiving enough bandwidth or prioritisation to handle peak usage.
If your entire VoIP system starts going offline regularly or crashing under pressure, it’s a clear sign that your network is overwhelmed or a hardware component is failing.
General network slowdown
If other network activities like file transfers or web browsing begin slowing down or lagging frequently, but your VoIP system remains working well, it’s a sign of appropriate QoS (Quality of Service) configurations.
However, your network has become insufficient to support your business activities and should be upgraded as a priority.
Uneven VoIP performance across sites
A telltale sign of bad VoIP network design in multi-site businesses is varying call quality levels across multiple locations. It means your wide area network (i.e., your business network across all its sites) is not handled appropriately.
Either your business has not adopted SD-WAN for optimal multi-site routing of your VoIP system, or it has not configured it correctly.
Troubleshooting VoIP traffic issues
You’ve been left with a VoIP system that struggles with peak traffic, and your major network upgrades (e.g. a failover connection for your leased line or a new network switch) will take some time to implement.
In the meantime, you must play VoIP doctor and manage the symptoms to ensure your colleagues can keep the ship afloat. Here are some quick fixes you can implement to improve VoIP traffic issues.
1. Adjust network prioritisation
Start by tweaking your Quality of Service (QoS) settings to ensure VoIP traffic is prioritised. Adjust your router and switch configurations to give VoIP packets precedence over less critical data. Minimise network hops by simplifying your network topology. If you haven’t already, segment your LAN to isolate VoIP traffic.
Throttle down or restrict non-essential traffic like video streaming or large file transfers, especially from your guest WiFi or employees’ devices. Your goal is to dedicate the highest-quality bandwidth to VoIP. If necessary, outright block bandwidth-intensive applications during peak times.
2. Optimise VoIP configuration
Once you’ve secured premium bandwidth for VoIP, refine your VoIP system settings to reduce resource usage without compromising call quality.
Switch to lighter, low-bandwidth codecs like G.729 that maintain reasonable audio quality and fine-tune jitter buffer settings on individual VoIP devices to reduce audio lag, packet loss, and call disruptions. While this might require some trial and error, these adjustments can provide noticeable peak-time improvements.
3. Call management
If necessary, implement Call Admission Control (CAC) to temporarily limit the number of simultaneous active calls to prevent your system from being overwhelmed.
Encourage non-critical calls to be scheduled during off-peak hours or rerouted through less-prioritised network paths. You might also temporarily reroute low-priority calls to alternate communication platforms to reduce the strain on your primary VoIP system.
Traffic-resistant VoIP phone systems
A properly implemented VoIP system is designed to perform reliably under stresses exceeding peak traffic conditions. In contrast, outdated or poorly configured VoIP systems and business networks struggle to handle increased traffic, leading to performance issues.
Let’s compare how each handles traffic:
| Component | Congestion-Proof VoIP System | Congestion-Prone VoIP System |
|---|---|---|
| Broadband Connection | Utilises leased line with broadband speeds up to 10Gbps, ensuring dedicated and consistent bandwidth and broadband scalability for VoIP. Redundant connections offer failover during outages, while traffic shaping prioritises VoIP packets for stable call quality even at peak times. | Relies on basic shared broadband, leading to inconsistent speeds and limited bandwidth. Lacks redundancy or traffic prioritisation, resulting in frequent dropped calls and poor quality under congestion. |
| Firewalls | Employs enterprise-grade firewalls with deep packet inspection (DPI) to prioritise VoIP traffic and block cybersecurity threats. Scalable virtual firewall instances accommodate high-demand scenarios, with regular updates enhancing security. | Uses basic firewalls with minimal protection. DPI and traffic prioritisation are absent, leaving VoIP traffic vulnerable. Scalability and update support are limited, increasing exposure to threats. |
| Router | High-performance routers with QoS prioritise VoIP packets, reducing latency and jitter. Supports SD-WAN and SASE to optimise traffic between multi-premise sites, with regular firmware updates and integrated threat intelligence for added resilience. | Standard routers lack QoS, resulting in jitter and packet loss. No SD-WAN support leads to inefficient traffic management for multiple locations. Often outdated, with poor security and no updates. |
| LAN Hardware | Managed switches with VLAN isolate VoIP traffic for better performance and security. Gigabit Ethernet ports reduce latency, while modular setups enable easy expansion to support growth. | Unmanaged switches combine all traffic, causing congestion and degraded performance. Limited-speed ports create bottlenecks, and static setups require costly overhauls for scalability. |
| Network Configuration | Advanced configurations use QoS, load balancing, and AI-driven resource management to prevent congestion. SD-WAN ensures optimised traffic across multiple premises, with real-time monitoring and robust failover policies maintaining reliability. | Basic configurations lack traffic management or monitoring, leading to inefficiencies. No SD-WAN support for multi-site businesses, and no failover strategies result in prolonged outages. |
| VoIP System | Combines modern hardware with adaptive codecs like Opus for efficient bandwidth use and superior quality. VoIP Integrations with collaboration tools (e.g., MS Teams), UCaaS with cloud-based PBX enabling scalability. AI-driven traffic control and real-time monitoring optimise performance and reduce congestion. | Outdated hardware and software rely on inefficient codecs, consuming more bandwidth for poor quality. No integrations with modern tools, and traditional PBX systems lack scalability or congestion management. |
| Advanced features | Contemporary VoIP systems have advanced VoIP features like virtual assistants and smart call routing that improve call handling and VoIP integrations with CRM, ERP and -ecommerce software that help your agents handle enquiries significantly more efficiently. | An outdated VoIP system only has basic call management functions like forwarding and simultaneous phone ringing. A lack of integrations and advanced features results in less efficient calls and post-call workflows. |
These differences are also evident when displayed graphically. Both the outwards broadband connection and the local area network (LAN) make a big difference.
The inadequate setup has limited shared bandwidth typical of connections like SoGEA or even full fibre business broadband, a router with limited functionality, and an outdated self-hosted VoIP system that lacks segmentation and sufficient bandwidth.
In contrast, the robust system is supported by a 10Gbps leased line business broadband that supports ample symmetrical bandwidth, an advanced business broadband router supporting QoS and advanced firewalls, and a network switch that enables VLANs and network segmentation.
Implementing a VoIP system that handles high-traffic
Now that you know how to troubleshoot your VoIP and the best practices to ensure your VoIP can handle high traffic, it’s time to see lay the steps on how to implement it:
1. Assessing your current VoIP infrastructure
Start by contacting your VoIP provider or IT department (whoever manages your system) and running a comprehensive network audit.
This involves taking inventory of your network and its bottlenecks and then observing its performance over time under different traffic conditions. Here’s what your network assessment should include:
- Network inventory: Record your entire network composition to ensure you’re considering everything, including broadband contracts, routers, switches, servers, cabling, mesh networks, etc.
- Bandwidth usage: How much bandwidth does your VoIP system require compared to what’s available during peak usage? Measure this to see if there’s a gap.
- Latency, jitter, and packet loss: Key metrics affecting call quality. Latency should ideally be under 150 ms, jitter under 30 ms, and packet loss near 0%.
- Traffic prioritisation: Check if VoIP traffic is being prioritised on your network. If not, QoS settings might need to be adjusted.
- Capacity under load: Simulate high traffic conditions (e.g., multiple simultaneous calls and high network traffic) to see if your system maintains call quality or degrades.
- Existing failover mechanisms: Evaluate whether your system has redundancy to handle outages or sudden traffic surges.
- Scalability: How many times the capacity of your existing network will you need to fit in your business’s projected traffic growth? What buffer would you like to have on top of this?
2. Outsourcing to experts
VoIP and business networks are not simple and require significant resources. In the age of “anything-as-a-service”, businesses are outsourcing these niche applications to experts to ensure they get a system that can handle high traffic without having to do this in-house.
This lets businesses focus on the quality of their services instead. Request a callback from our VoIP experts if your system is showing symptoms of poor congestion management or simply if you want to ensure it can handle its future needs.
3. Incidence Response Plans (IRPs)
Even the most resilient VoIP system can encounter unexpected traffic spikes or disruptions due to misconfiguration or successful cyberattacks. A well-defined Incident Response Plan (IRP) ensures you’re prepared to address issues and minimise poor performance or outright downtime.
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