Communication
What if there was a magical way you could connect your legacy and complex devices to Microsoft Teams? If Teams Phone could be the sole phone system you need worry about forever more?
Sounds pretty good, right? Imagine a world where your DECT handsets, your analog devices, and even paging systems all worked with Teams.
That’s right. Thanks to the Microsoft SIP gateway, which is now interoperable with tons of devices, you can connect almost anything to Teams.
What is the Microsoft Teams SIP gateway?
The Microsoft SIP Gateway is a cloud-based service that enables organizations to connect compatible SIP (Session Initiation Protocol) devices—like legacy desk phones—to Microsoft Teams. This allows businesses to extend the life of their existing telephony hardware while transitioning to Teams Phone for calling and collaboration.
The dream for many IT managers and PBX admins.
When asked about the success of the Microsoft SIP gateway, Tom Arbuthnot, who’s recently launched ChangePilot to deal with the overwhelm of Microsoft changes and new introductions, said:
“Teams SIP Gateway initially served as a bridge solution, designed to help customers leverage their existing SIP IP phone investments during the transition to Microsoft Teams. However, customer demand for specialized endpoint capabilities—including DECT, paging systems, and analog device support expanded its role.
A notable development over the past two years has been the addition of new SIP IP phones from both Poly and SNOM. While Microsoft positions Teams Phone devices as the premium physical phone experience, some customers want simple SIP phones with traditional physical keypads.”
A notable development over the past two years has been the addition of new SIP IP phones from both Poly and SNOM. While Microsoft positions Teams Phone devices as the premium physical phone experience, some customers want simple SIP phones with traditional physical keypads.”
What can you use the Microsoft Teams SIP gateway for?
Let’s explore the main use cases and devices you’re likely to use the SIP gateway for.
A full list of compatible devices is updated regularly on the Microsoft website.
1. DECT handsets
Spectralink was first to market with its integration for the SIP gateway. You can now use any of the following handsets with Teams:
- Spectralink 72 Series: Ruggedized for manufacturing and retail
- Spectralink 75 Series: Designed for industrial environments
- Spectralink 76 Series: Offers advanced features for enterprise use
- Spectralink 77 Series: Tailored for healthcare with disinfectant-resistant design
Another popular option is the Poly Rove series, accompanied by options from Ascom, Gigaset, and Yealink.
These are compatible with the SIP gateway thanks to native integration. Once set up, you can use DECT handsets in environments like warehouses, shop floors, and cargo ships to finally bring all your calling needs into Teams Phone.
That means your entire business is on the same calling tariff and all departments get connected and administered on the same platform.
2. ATAs
If you have analog devices still in use from your previous PBX deployment, you can now connect the majority of these to Teams Phone using an analog telephone adapter (ATA).
Supported devices include:
- Poly (OBI 300, OBI 302)
- Cisco (ATA 191, ATA 192)
- AudioCodes (MP-112 FXS, MP-114 FXS, MP-114 FXS_FXO, MP-118 FXS, MP-118 FXS_FXO, MP-124 FXS)
In use cases like lobby phones, shared phones, or emergency phones, there’s little justification for buying a brand new device when the old one functions just fine. However, until the introduction of the SIP gateway, it’s been standalone; disconnected from Teams.
Now, using any of these supported ATAs, you can bring analog devices into the Teams Phone mix.
Note: You can’t configure said analog handset in the same way as a native device. Instead, you provision the ATA to Teams Phone and you rely on the capabilities of the analog device itself. So you get things like dial time and perhaps call transfer, but there’s no ability to add the Teams interface, etc.
3. Paging systems
When we think of paging, it’s easy to get stuck in the thoughts about power-happy managers calling people into their office—or is that just my suppressed memory surfacing?
Overhead paging and alerting plays a vital role in the safety of staff, children, and vulnerable people in a variety of environments. Take an extreme weather alert when a storm is about to hit.
Here, sending an all-staff email just won’t cut it. Instead, opt for dialing a shortcode or using a touch screen to alert the entire building they need to gather in your designated assembly point.
You get an audible alert, a contextual pre-recorded message, and have the option to use traditional paging as a failsafe.
At Commsverse, the Microsoft community event in the UK, I spent some time at the Algo stand learning about how its devices are significantly smarter than “standard paging”.
For example, you can choose devices that come with noise isolation technology, hands-free visitor communication, and two-way speech. Paging isn’t simply loud messages over a tannoy system. It’s smart technology that’s now interoperable with the SIP gateway.
Other paging solutions compatible with the Microsoft SIP gateway include:
| Vendor | Devices(s) |
| Algo Solutions | Horn speaker, ceiling speaker, speaker with clock, paging adapter and scheduler, zone paging adapter. |
| CyberData | Paging server, amplifier, intercoms and horn |
| TonMind | Paging adapter with built-in amplifier |
| ZYCOO | Paging gateway with amplifier and intercom |
4. Fax
While not supported by Microsoft—as the SIP gateway is exclusively reserved for voice—some organizations have created their own fax workaround for Teams.
You can achieve this using the AudioCodes MediaPack 114/118/124 series. Mohanv1325, a user in the Microsoft Tech Community, confirmed the below:
“We are using fax with Microsoft SIP devices with Audiocodes Mediapack 114,118 and 124. On the Mediapack configure SIP signaling method either Fax Fallback or G711 to work with Microsoft SIP gateway.”
You’ll need to ensure proper QoS and open UDP ports (49152–53247) and TCP 5061 per the SIP Gateway planning guide. However, this is not supported by Microsoft and is only a workaround solution.
5. SIP-native devices
Obviously, being a SIP gateway, you can bring your existing SIP phones into Teams without any hassle.
Today, you can plug in almost any standards-based SIP endpoint and have it behave like a Teams phone. That means you get dial-tone, transfers, hold/resume, voicemail and message-waiting indicators—all over Teams Phone.
You can now use any of the following SIP-native handsets and conference phones with Microsoft Teams:
- Cisco Multi-Platform Series (7811, 7821, 8845)
- Poly VVX & CCX family (VVX 250/350/450, CCX 500/600)
- Yealink T4S & T5S series (T46S, T48S, T54W, T58A)
- AudioCodes C450HD & C470HD
- Snom D7xx range (D785, D785-S)
- Grandstream GXP16xx & GXP21xx
- Shoretel (Mitel) 230 & 5600 series
- Conference phones: Poly Trio C60, Yealink CP965
Because these devices speak SIP natively, you provision them in the Teams Admin Center (or via your Direct Routing SBC) just like any other SIP endpoint.
Limitations of the Microsoft Teams SIP gateway
The biggest thing to be aware of when using the SIP gateway is that Microsoft only supports what it confirms it supports. While fax is possible via a custom workaround, Microsoft is very strict on the SIP gateway only officially supporting voice traffic.
Within its planning documentation, Microsoft also notes several warnings and notes per brand/device:
- For Poly devices, LLDP must be turned on at switch level for subnet length based dynamic location discovery.
- Compatible Cisco SIP IP phones support dynamic location discovery over LLDP only.
- Customers can use AudioCodes OVOC and Poly Lens to manage device side configuration of their AudioCodes 400 series and Poly VVX/Trio devices respectively.
- Spectralink Handsets receive firmware updates over the air from Spectralink IP-DECT servers.
- Ascom Handsets receive firmware updates over the air from Ascom IP-DECT servers.
- Gigaset Handsets receive firmware updates over the air from Gigaset IP-DECT servers. All Gigaset PRO DECT Handset models are compatible with Microsoft Teams SIP Gateway.
- For Yealink DECT Base Stations, use the appropriate region specific firmware version from the list to have the best calling experience.
- For some devices, the minimum firmware version is greater than the approved firmware version. This is because the 3.X version is the Skype for Business version. We update the SIP version which is 2.X.
Getting started with the Microsoft Teams SIP gateway
Whether it’s DECT, ATA, or paging that piques your interest the most, the SIP gateway has opened the door to true unified communications when it comes to Teams Phone.
You no longer have to run several administration portals, there’s no longer multiple bills for phone and calling, and all your users and devices are connected on the same platform.
When the good folks at Microsoft preached productivity, efficiency, and teamwork, this is more like what they meant. When everything in your VoIP environment is connected, you can finally say Teams Phone is a business phone system. The SIP gateway significantly helps that.
That said, setting up everything for a Teams roll out is a time-consuming, change-heavy process that needs meticulous planning and expert guidance. Whether you’ve been waiting for the SIP gateway to cover off everything you need to start your implementation or you have a bulk migration of devices you can now undertake, we’re confident we can help. After all, we were awarded Microsoft Partner of the Year in 2023 and named a finalist again in 2024.
When you choose Cloud Revolution for your Teams Phone implementation, you’re signing up to:
- Specialized Focus: We live and breathe Microsoft Teams and Copilot. From complex voice migrations and Teams Rooms implementations to Copilot agent development and Dynamics 365 contact center solutions, our expertise covers every scenario—no matter how complex.
- End-to-End Partnership: We’re with you at every step: planning, ideation, implementation, training, and continuous improvement. Our proven frameworks reduce project friction and accelerate time to value.
- Outcome-Driven Approach: Customers routinely see measurable gains-like a 45% ROI and payback in under 6 months from Teams Phone deployments. We’re passionate about delivering results that transform your business.
Need help with the SIP gateway?
Book a free call with our Teams people here.
