SIP trunk providers compared — Telnyx, Flowroute, VoIP.ms, Bandwidth, Twilio

Your VPS PBX needs a SIP trunk to make and receive calls on the public phone network. LYLIX doesn't bundle one — bring your own. Five providers come up regularly: Telnyx, Flowroute, VoIP.ms, Bandwidth.com, and Twilio. This article compares them honestly so you can pick on first deploy.

Pricing snippets below reflect the providers' public rates at the time this article was last updated; carrier pricing changes — verify on the provider's current rate page before committing.

The 30-second comparison

Pick Telnyx if

• You want the best balance of price, quality, and developer-friendliness.
• You'll do any SMS / MMS / 10DLC work — their A2P registration process is the cleanest in the field.
• You want STIR/SHAKEN attestation that actually shows up correctly on the receiver's caller ID display.
• You appreciate clear, predictable per-minute pricing without "Reserved Capacity" gotchas.

Pick Flowroute if

• You want IP authentication (no SIP credentials to leak / brute-force).
• You're running a hands-off setup where reliability + simplicity outweigh advanced features.
• You're already configured for them from a previous PBX (zero-friction continuation).

Pick VoIP.ms if

• You're cost-sensitive — they have the lowest per-DID rates and unlimited-plan options for high-volume.
• You want lots of POP options for latency optimization (many cities globally).
• You're comfortable in dense admin UIs and don't need much hand-holding.

Pick Bandwidth.com if

• You're operating at volume (hundreds of concurrent channels, large DID inventories) and want a contract-based relationship with a tier-1 carrier.
• E911 compliance matters (they're the strongest of the bunch).
• Audio quality is non-negotiable — they own much of the US telecom infrastructure end-to-end.

Pick Twilio if

• You're building a voice product, not just hosting a PBX. Their SDKs (Python, Node, Java, etc.) make programmable voice trivial.
• You need global reach — they have local DIDs in 100+ countries.
• Your team is already using Twilio for SMS / WhatsApp / etc. and wants unified billing.
• Per-minute cost isn't your primary constraint.

Comparison-shopping tips

• Test before committing. Most providers offer small free trial credits ($10-25). Send 100 outbound calls + 100 inbound through each candidate, listen to the audio, check the receiver's caller ID display, time the post-dial delay.
• Don't put all your eggs in one trunk. Multi-trunk setups (primary + failover to a second provider) are standard for any business that can't tolerate trunk outages.
• Watch for "soft fees." Some providers charge for things you wouldn't expect — DID porting, unblocking after fraud, premium support tiers, after-hours technical support. Read the fee schedule before committing.

Multi-carrier failover setup

FreePBX® trunks support failover natively — configure primary + secondary trunks, set the outbound route to try primary first, fall through to secondary on registration failure or specific SIP response codes. Test the failover before relying on it:

# Simulate primary down
iptables -A OUTPUT -p udp -d <primary-trunk-IP> --dport 5060 -j DROP
# Place a call — should route through secondary
# Then restore
iptables -D OUTPUT -p udp -d <primary-trunk-IP> --dport 5060 -j DROP

Same shape on FusionPBX® via gateway failover.

The trademark caveat

None of these providers are affiliated with LYLIX. We don't resell their service; you sign up directly and configure your VPS PBX to use them. Their service quality, billing practices, and fraud-protection policies are theirs, not ours. Read their terms before sending production traffic.