Linkus Cloud Service Pro


Connect with Peace of Mind

If you’ve ever been troubled by the technical and security hassles in connecting remote workers, branch offices, or remote SIP terminals to your central office S-Series VoIP PBX, then you should take Linkus Cloud Service Pro.

Leveraging the enterprise-grade tunneling technology, Yeastar Linkus Cloud Service Pro (LCS Pro) clears all obstacles of remote SIP access & communications for S-Series VoIP PBX users. It provides encrypted remote connection for Linkus UC Clients in no time and offers a dedicated PBX domain name (FQDN) for secure, effortless registration of remote SIP endpoints to the PBX. Wherever your teams work and whatever SIP devices you use, rest easy with secure and uninterrupted business communications, irrespective of the locations.

Linkus Remote Connection

Your Office Anywhere with Linkus UC Clients

All the power of an enterprise phone, now in your pocket. LCS Pro not only
minimizes your Linkus-related server configuration to a simple click, but
enables a full spectrum of Unified Communications options on your Linkus
UC Clients, so your teams can call, chat, and collaborate—at home, in the
office, or somewhere in between—with unsacrificed productivity.


One app for all communications


Everything from the one-touch dialing & call management to the advanced
instant messaging, file sharing, presence, and contacts management. You
get all the office extension tools to get work done, from anywhere.


No complex network settings


It takes only one click for you to set up Linkus server for remote
communications. You don’t need to open a port on your PBX’s intranet
firewall. We do all the backend connections with inbuilt security and


Stopped NAT issues for reliable calling


The quality of a VoIP call is heavily dependent on the environment that
the call is running in. Yeastar LCS Pro stops the NAT issues from
happening and provides a reliable call environment to improve the call

Linkus UC Clients

Remote SIP Service

Effortless Remote SIP Connections

Setting up remote offices and phones can never be easier. The Yeastar-supplied PBX domain name (FQDN) helps you quickly establish a private tunnel for remote SIP registrations to your PBX. It’s easy and secure to register your remote IP Phones, branch office PBXs, gateways, and alike SIP endpoints to your central office PBX, as if they were deployed on the intranet.

Remote SIP Service


Dedicated PBX Domain Name

Get a fully qualified PBX domain name (FQDN) that frees you from the risky, complicated PBX port forwarding when it comes to remote SIP endpoints registration to the PBX.


Rigorous Remote Access Control

Allow remote access only to the permitted SIP endpoints. You have complete control over which IP addresses and Extension accounts can register or connect remotely to the PBX.


Shared Business Resources

Through the remote connection, your remote offices and SIP terminals become parts of the central office PBX system and can share the PBX’s resources.

The Security Matters

Shield your company from the potential risks of PBX network penetration and subsequent issues of toll fraud, data breaches, and cyber-attacks alike. The Remote Access Service leverages the enterprise-grade tunneling technology and encryption algorithms to best protected your remote communications and system access.


Separate and Private Connection


LCS Pro leverages a private tunneling server for data transmission between the PBX and the remote SIP endpoints. Your PBX’s IP address won’t be exposed to the public. All remote connections are direct, undercover, and double safeguarded with account authentication.


Impenetrable Encryption


Each PBX has its own encryption key contributed by sophisticated encryption algorithms, ensuring you a peace of mind.

The Security Matters

It’s a must-have for
remote workers

Loved by Customers Worldwide

It’s a must-have for remote workers. There is no complex VPN and no security risks exposing PBX. With all the great features on Linkus softphone, we nailed it with easy and seamless interoffice communications.

Miguel Rabi

Optical Networks, Peru

I use the service daily and
enjoy it thoroughly.

Loved by Customers Worldwide

By utilizing the service for our branches, our technicians and sales can now communicate with each other and clients - on any given day, from anywhere in the country. I use the service daily and enjoy it thoroughly

Morne du Plessis

MFP Office Automation Group, South Africa

The service security and
reliability really
made a difference.

Loved by Customers Worldwide

Now we can have teleworker extensions without exposing our PBX to the internet. It also solves the double or triple NAT from my home internet provider. The service security and reliability really made a difference.

Miguel Rabi

Optical Networks, Peru

It is very easy to
install everything.

Loved by Customers Worldwide

It changed the way we communicate. Both the Linkus mobile and desktop apps are functional, fast and guarantee excellent audio quality. Best of the all, it is very easy to install everything.

Tommaso Grumo

Sistemi di Comunicazione s.n.c.

Use Linkus UC Clients to
conduct business.

Loved by Customers Worldwide

Our customer Rembe has a bunch of employees traveling back and forth the USA and Germany. They were most impressed with being able to use Linkus UC Clients to conduct business while on the road, hotel rooms and being in either country.

Eric Martin

IP3 Solutions, LLC, USA.

Get Started with the Service

And bring your people, office, and devices together easily, securely—from anywhere

Frequently Asked Questions

What Yeastar products can be used with LCS Pro?

Linkus Cloud Service Pro is a value-added service designed for Yeastar S-Series VoIP PBX and can only be used with S-Series VoIP PBX.

If you are using Yeastar P-Series PBX Appliance or Software Edition, you can subscribe to the P-Series Enterprise Plan or above to enjoy the functionality of Linkus remote connection and remote SIP service.

When do I need LCS Pro?

If you are using S-Series VoIP PBX and match one or more of the following conditions, you should definitely give Linkus Cloud Service Pro a try!

You need a softphone that is easy to configure; You need a softphone that can be used outside of the company network; You need unified communications features with your softphone; You need to register remote IP Phones to the PBX system; You have branch office PBX and want to connect it with your S-Series VoIP PBX; You focus on system security and want to avoid the risky PBX port forwarding when it comes to the remote SIP registration and access.

Is there a free trial available?

Yes! We provide 30-day free trial for Linkus Cloud Service Pro. You can log in your S-Series VoIP PBX and go to “Linkus”. Under the “Linkus Cloud Service Pro” tab, click the “Enable Linkus Cloud Service Pro” button to have a try.

Do I have a Cloud PBX if I purchase LCS Pro?

No. Only S-Series VoIP PBX needs Linkus Cloud Service Pro, and it does not make your PBX a Cloud PBX.

I have subscribed to LCS. Can I upgrade to LCS Pro?

Yes! As an upgraded plan for Linkus Cloud Service (LCS), Linkus Cloud Servce Pro (LCS Pro) includes everything in the Linkus Cloud Service plus the additional features of dedicated PBX domain name (FQDN) and Remote SIP Service, allowing you to register remote IP Phones, Gateways, branch office PBXs, and alike SIP endpoints to the PBX effortlessly, securely, and without port forwarding.

For the service upgrade, you can upgrade it direclty on Yeastar website here or contact your local Yeastar service provider for help.

How secure is LCS Pro?

Linkus Cloud Service Pro is an application-level tunneling service; it only handles SIP data and the custom protocol data of the Linkus and the connected remote SIP endpoints. It does not touch the PBX data, which means no party can access the PBX through the tunneling server.

All transmission between the PBX and the tunneling server is encrypted. And each PBX will have its own encryption key. Even if the tunneling server is brought down by a hacker, there is no way to replace the tunneling service and get original transmission data since the hacker does not know the encryption method.

The tunneling server is secure and has multiple protection measures. Our operation team stands by to handle any emergency in no time.

Furthermore, for the Remote SIP Service, you can customize remote SIP access authorization by extension and apply IP restriction to further secure all the remote SIP access.

Why I can’t find the LCS Pro settings on my PBX?

Linkus Cloud Service Pro is only supported on the listed S-Series VoIP PBX firmware version and above. You will need to upgrade your PBX firmware based on your PBX hardware version.

S-Series V2 hardware: firmware version and above; S-Series V4 hardware: firmware version and above; S50i VoIP PBX: firmware version and above.

For details on how to upgrade the firmware on your S-Series VoIP PBX, please refer to this firmware upgrade guide.

Where can I download Linkus UC Clients?

Linkus UC Clients for Windows, Mac, iPhone, and Android can be downloaded from here.

How can I purchase LCS Pro?

Log in your S-Series VoIP PBX and to go “Linkus”, click the “Buy Service” button to purchase Linkus Cloud Service Pro. Or you can click this link to purchase directly; in this case, you will need to enter your PBX’s serial number manually. You can also contact your local Yeastar service provider directly for the purchase or support.

Which payment methods are accepted?

We accept payment by PayPal, by credit card (VISA / MasterCard / AMERICAN EXPRESS / Discover Card), and by offline payment (with payment instruction via email).

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