VoIP Calls Not Working? Here’s How to Fix It (and Why FTTP Helps Birmingham Businesses)

If you’re in Birmingham and your VoIP calls are crackling, dropping, or one-way only, you’re not alone. We fix this every week across the Jewellery Quarter, Digbeth, Colmore Row, Aston and Hockley. We’re VoIP specialists: feature-packed licences (think call recording, IVR call routing  “press 1 for Sales, 2 for Support”) and a wide range of reliable Yealink desk, DECT and Android phones. Most call issues have a clear cause and a clean fix. Long term, the best foundation is almost always full fibre (FTTP) set up correctly for voice.

Why your VoIP calls are not working (In plain English)

Voice quality lives and dies on latency, jitter and packet loss. When your upload is busy, cloud backups, CCTV feeds, big file syncs, your calls arrive late or indistinguishable. Add noisy Wi-Fi, long runs, or a router with SIP ALG and double NAT, and you get stutter, robotic audio or silence in one direction. Older FTTC/ADSL links magnify this because the upstream is tiny; one upload can wreck an entire call queue.

Five-minute fix you can try now

Do one clean test on a wired connection, then restart ONT → router → phone in that order. Pause heavy uploads, try another Ethernet port/cable, and temporarily disable SIP ALG. If the same extension sounds perfect on a mobile app over 4G/5G, your office link or router config (not the phone system) is the bottleneck. If you're struggling to achieve the steps listed above reach out and we can walk you through it free of charge.

Fixes for your VoIP Phones no matter the brand or supplier

Start by telling the network that voice matters. Enable QoS so VoIP packets jump the queue, and separate voice from general traffic with a simple voice VLAN. Schedule backups for evenings, choose cleaner Wi-Fi channels or add one extra access point where signal is weak, avoid double NAT, and keep firmware current. Lock devices to gigabit ports so they don’t negotiate down.

Why Full Fibre Business Broadband solves the root cause

Full fibre brings low, stable latency and serious upload headroom, so your calls don’t compete with everything else. On copper-based links, the upstream collapses under load; on FTTP, there’s space for voice, video and cloud without the drama. For most SMEs, FTTP is the right base for VoIP, Teams/Zoom, CCTV and SaaS. If you run mission-critical workloads and need guarantees, a leased line adds dedicated, un-contended bandwidth and tight SLAs.

What we see happening with VoIP in Birmingham City Centre and surrounding area's

Typical patterns: FTTC(BT SoGEA) offices that sound fine in the morning and awful after lunch when syncs kick in your VoIP calls are not working; multi-tenant buildings with congested Wi-Fi; legacy routers with SIP ALG causing one-way audio; and postcodes told “no fibre” even though partner-only networks have spare capacity. We cross-check multiple carriers, confirm live availability, and when needed, put real eyes on site so you get a straight answer. In Birmingham City and surrounding areas we can almost guarantee Full Fibre even if you've been told it's not possible and you don't need to take our word for it.. our Google reviews speak for themselves.

Your path to crystal clear VoIP Calls

We start by checking your address across multiple networks (including partner-only fibre). If FTTP is available, we’ll recommend the right tier and prepare a simple install plan; if uptime is absolutely critical, we’ll price a leased line. On the day, our engineer sets up the router, prioritises voice, and runs live test calls. We port your numbers without interrupting service and, if you want belt-and-braces resilience, add 4G/5G failover and smart call-forward rules.

FAQs

My VoIP phone isn't working, where do I start?

Test on a wired connection, restart equipment in order, and disable SIP ALG. If calls are perfect on a mobile app over 4G/5G, the issue is your office link or router config.

Why do VoIP calls keep dropping?

Usually upload congestion, Wi-Fi interference, or NAT/ALG quirks. Prioritising voice and moving to FTTP stabilise things quickly.

We get no audio / one-way audio - what causes that?

Often SIP ALG, double NAT, or closed ports. Turn off ALG, avoid double NAT, and open the ranges your provider needs.

Do we need a leased line for good voice?

Not always. FTTP plus sensible QoS is perfect for most teams. Choose a leased line when you need guaranteed performance and SLAs.

Can we keep our numbers?

Yes, we port them and plan cutover out of hours if needed.

Ready to make your VoIP work properly?

Check FTTP at your postcode and we’ll map a clean, no-drama upgrade. We handle the survey, install, number porting and on-site setup, plus Yealink hardware and feature-rich licences (call recording, IVR routing, analytics) so your team can just get on with work.

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Call: 0121 798 2508 Email: info@powerfibre.co.uk

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