Bandwidth, Telnyx, and SIPNEX represent three different approaches to the SIP trunk market. Bandwidth is the wholesale giant — the carrier behind many other carriers. Telnyx is the developer-friendly platform with its own infrastructure. SIPNEX is the operator-owned carrier purpose-built for dialers. Each excels in a different context, and choosing the wrong one costs you either money, performance, or both.
This is a three-way comparison written by SIPNEX. We compete with both. We will tell you which one to choose based on your operation type. See our individual comparisons for deeper analysis: Twilio vs SIPNEX, Telnyx vs SIPNEX, and our Best SIP Trunk Providers overview.
Quick comparison
| Factor | Bandwidth | Telnyx | SIPNEX |
|---|---|---|---|
| Type | Wholesale carrier | CPaaS with own network | Direct carrier |
| FCC License | Yes | Platform operator | Yes |
| Own STIR/SHAKEN cert | Yes | Yes | Yes |
| A-level attestation | Yes | Yes | Yes |
| Concurrent channels | Account-dependent | Scalable (may charge per-channel) | Unlimited, no fee |
| Published pricing | No (enterprise sales) | Yes | Yes |
| Developer API | Yes (enterprise) | Yes (extensive) | No |
| Billing increment | 6-second | 6-second | 6-second |
| VICIdial-specific support | No | No | Yes |
| Minimum commitment | Often required | Varies | None |
| Best for | Enterprise, CPaaS companies | Developers, mid-market | Dialer operators |
Bandwidth
Strengths: The largest underlying voice carrier in the US. If you are buying from any other provider, there is a good chance your calls transit Bandwidth’s network at some point. Direct carrier status with full FCC licensing and regulatory compliance. Excellent network quality and reliability. Strong peering relationships across the US.
Limitations for call centers: Enterprise sales model — you typically need sales engagement to get pricing, and minimum commitments are common. Support is enterprise-tier, which means great for large accounts but less accessible for 20 to 100 agent operations. Not specifically designed for dialer workloads — they serve a broad market including UCaaS platforms, CPaaS companies, and enterprise direct. Per-channel or trunk-level pricing may apply.
Best fit: Enterprise operations with 500+ agents, companies building their own CPaaS or UCaaS products on carrier infrastructure, large-scale operations that can commit to significant monthly volumes and benefit from dedicated account management.
Telnyx
Strengths: Developer-friendly APIs with good documentation. Own network infrastructure (more than a pure reseller). Competitive pricing published on website. Broad product portfolio (voice, messaging, IoT, networking). Good international coverage with global points of presence.
Limitations for call centers: Platform overhead — you are paying for API infrastructure and developer tools that pure dialer operations do not use. Per-channel pricing may apply on some plans, adding cost for high-concurrency predictive dialing. Support is broad (covering their full product line) rather than deep in dialer-specific expertise.
Best fit: Technical teams building custom voice applications, mid-market operations that want API programmability with better pricing than Twilio, operations with international calling needs.
SIPNEX
Strengths: Purpose-built for predictive dialer and VICIdial operations. Unlimited channels with no per-channel fee. Published wholesale pricing optimized for high-volume outbound. Own FCC license, own STIR/SHAKEN cert, own 499 filing. Support team that runs VICIdial and understands dialer-specific issues. No minimum commitment.
Limitations: No developer API. US-focused (limited international coverage compared to Bandwidth or Telnyx). Narrow product focus — voice and DIDs only. Not suitable for building custom applications or platform-level products.
Best fit: Call centers with 20 to 500 agents running predictive or progressive dialing. VICIdial and Asterisk-based operations. Any high-volume US domestic outbound operation where cost, attestation, and support quality are the priorities.
The decision
If you are an enterprise building a communications platform → Bandwidth
If you are a technical team building a custom voice application → Telnyx
If you are an operator running dialers at volume → SIPNEX
If none of these fit cleanly, consider: what is the most expensive problem in your operation? If it is per-minute cost → compare SIPNEX and Bandwidth. If it is developer velocity → compare Telnyx and Twilio. If it is answer rate → the carrier with direct A-level attestation and CID reputation management support wins regardless of other factors. All three carriers listed here can provide A-level attestation, but SIPNEX is the only one with support that actively helps operators manage CID strategy.
Frequently asked questions
Which carrier is cheapest for high-volume outbound?
At 500,000+ minutes per month of US domestic outbound, SIPNEX and Bandwidth offer the most competitive wholesale rates. SIPNEX’s published pricing and lack of per-channel fees make total cost calculation straightforward. Bandwidth’s enterprise pricing requires sales engagement but may be competitive at very high volumes (5M+ minutes). Telnyx is competitive but potential per-channel fees and platform overhead can add cost at high concurrency. Compare total monthly cost — not just per-minute rate — across all providers, including channel fees, platform fees, and DID costs.
Do all three provide A-level STIR/SHAKEN attestation?
Yes. All three hold their own STIR/SHAKEN Service Provider certificates and can sign at A-level for numbers provisioned through their platforms. The attestation quality is functionally equivalent across all three for standard use cases. The difference is in how each handles edge cases (ported numbers, third-party DIDs, complex configurations) and in the support available when attestation issues arise. SIPNEX’s narrow focus on dialer operations means attestation-related support is a core competency rather than a secondary feature.
Can I switch between these carriers easily?
Yes. All three use standard SIP protocol, so switching involves changing SIP proxy credentials in your PBX configuration, porting your phone numbers to the new carrier (7-14 business days for LNP), and testing the new trunk before cutting over completely. You can run two carriers simultaneously during the transition — old carrier for numbers still porting, new carrier for newly provisioned DIDs. The SIP protocol standardization that all three support means you are never locked in to a proprietary technology.
SIPNEX is the carrier built for operators. Unlimited channels, A-level STIR/SHAKEN, published wholesale rates, and support from people who run VICIdial. Test us against your current carrier or see the rate card.
Keep Reading
SIPNEX
FCC-licensed carrier with its own STIR/SHAKEN SP certificate. Operator-owned. SIP trunks built for operators who dial at volume.