Choosing the right SIP-to-PRI device can make or break a deployment.
For service providers and MSPs bridging modern SIP trunks to legacy PBXs, the hardware sitting at the edge determines not just call quality, but interoperability, survivability, and support costs. In 2025, the top contenders — AudioCodes Mediant, Ribbon SBC 1000/2000, Cisco ISR with CUBE, Sangoma Vega, and Grandstream GXW4500 — each have their sweet spots.
This guide breaks down what “good” looks like in the field, compares the leading models, and helps you pick the right fit for your customer base and infrastructure.
TL;DR
If you need an SBC plus PRI in one chassis, pick AudioCodes Mediant or Ribbon SBC 1000 or 2000. If you only need a straightforward PRI gateway, Sangoma Vega 100G or 200G, and Grandstream GXW4500 are solid. If the site is Cisco centric, ISR 4K with CUBE and a PRI NIM is the cleanest path. (AudioCodes)
1) What “good” looks like in the field
SBC-grade interop and security when the site needs TLS, topology hiding, SIP normalization, and survivability. AudioCodes and Ribbon excel here, with current software and broad interop programs. (AudioCodes)
Simple TDM gateway when you just need a PRI handoff without SBC features. Sangoma Vega 100G or 200G and Grandstream GXW4500 are common. (Sangoma Portal)
Vendor alignment where existing operations, spares, and skills matter. Cisco ISR 4K with CUBE and a PRI NIM is often chosen in Cisco shops. (Cisco)
2) The short list
AudioCodes Mediant 800 or similar
Hybrid gateway and eSBC in one 1U, with PRI modules and rich SIP normalization. Current user manuals and quick guides cover PRI setup, IP groups, proxy sets, and routing. AudioCodes+1
Ribbon SBC 1000 and 2000
Enterprise edge SBCs with T1 or E1 cards, strong interop catalogs, and wizards for common PBXs and trunks. (RBBN Learning)
Cisco ISR 4K with CUBE and PRI NIM
Add a 1, 2, or 8‑port T1 or E1 NIM, run CUBE, and deliver PRI to the PBX. Official docs detail hardware, clocking, and CUBE SIP configuration. (Cisco)
Sangoma Vega 100G or 200G
Purpose-built SIP to PRI with branch survivability and flexible routing. (Sangoma Portal)
Grandstream GXW4500 series
Cost-effective 1, 2, or 4‑span gateways with TLS, SRTP, and T.38 support. (Grandstream)
3) Selection matrix
Requirement | Best fit |
|---|---|
SBC features plus PRI handoff | AudioCodes Mediant, Ribbon SBC 1000 or 2000 (AudioCodes) |
Simple PRI gateway, price sensitive | Grandstream GXW4500, Sangoma Vega 100G or 200G (Grandstream) |
Cisco operations, NetOps standardization | Cisco ISR 4K with CUBE and PRI NIM (Cisco) |
Need vendor interop catalog and wizards | Ribbon SBC 1000 or 2000 (Ribbon Communications) |
Frequent SIP header manipulation, complex dial plan | AudioCodes Mediant, Ribbon SBC 1000 or 2000 (AudioCodes) |
4) Deployment patterns that actually work
TLS to the SIP provider, PRI to the PBX. Choose a platform that supports TLS and SRTP, as it is the safer default and widely supported in current firmware and data sheets. (Grandstream)
Normalize all numbers to E.164 at the edge. Use transformation or manipulation tables on the gateway or SBC. Ribbon’s interop guides reference these constructs. (Ribbon Communications)
Treat clocking as a design item for PRI stability. Cisco and AudioCodes both document clocking and network sync considerations. (Cisco)
Whether you’re standardizing across sites or tackling one-off conversions, selecting the right SIP-to-PRI device means balancing reliability, vendor alignment, and feature depth. AudioCodes and Ribbon remain the safest bets for integrated SBC plus PRI, while Sangoma and Grandstream keep budgets in check for straightforward gateways. Cisco environments, of course, benefit from ISR with CUBE for clean, native integration.
If you’re a Viirtue partner, you already have access to configuration guides and interop notes for AudioCodes and Ribbon — saving you hours on setup and testing. Not yet a partner? Visit viirtue.com to learn how our white-label platform helps MSPs deploy and manage SIP trunks, SBCs, and UCaaS solutions more efficiently and profitably.
5) FAQs
What is the most popular choice today?
AudioCodes Mediant and Ribbon SBC 1000 or 2000 are the most common, where an integrated SBC plus PRI is required. (AudioCodes+1)
Do I need full SBC features?
If you require TLS, topology hiding, SIP header normalization, and survivability, yes. Otherwise, a simple gateway can be fine. (AudioCodes)
Can I keep my Cisco standard and still deliver PRI?
Yes, with an ISR 4K, a PRI NIM, and CUBE. (Cisco)
Are low cost gateways secure?
Grandstream GXW4500 supports TLS and SRTP. Hardening and proper provisioning still matter. (Grandstream)
What firmware should I run?
Use a current, vendor-recommended GA release before go‑live. AudioCodes and Ribbon publish active user manuals and IOT notes. (AudioCodes)
