SBC as a Service PakistanManaged AudioCodes & Ribbon SBCs
Microsoft and Zoom both require a certified session border controller before your carrier trunk can reach Teams or Zoom Phone. But buying one means a capital purchase, channel licenses, a second unit for failover, and an engineer who knows SIP. Capstar Solutions runs the SBC for you instead, as a subscription, and handles the carrier coordination, certificates, and security hardening that break most first deployments.
Why Can’t Teams or Zoom Calling Run Without an SBC?
Once your carrier trunk touches the internet, your phone system is exposed to attack. And your carrier, your PBX, and your cloud platform each speak a slightly different version of SIP. A session border controller (SBC) sits at the edge of your network and solves both problems. Without one, Microsoft Teams Direct Routing and Zoom Phone BYOC won’t connect at all.
It Translates
Converts between your carrier, PBX, Teams, and Zoom, so every call connects.
It Guards
Works as a voice-built firewall, keeping attackers and toll fraud out.
Your existing firewall can’t do this job. It doesn’t read SIP, it can’t renegotiate codecs, and it won’t spot a toll-fraud pattern until the bill arrives. A dedicated SBC service protects and manages every SIP session on your network. It keeps voice, video and instant messaging secure across public and private networks, following the architecture set out in IETF RFC 5853. Here is what the session border controller Pakistan enterprises get from Capstar Solutions does for you on every call.
Most gateway problems are cabling, signalling or dial-plan problems. That is where our engineering time goes.
Calls that Connect the First Time
Your carrier, Teams, Zoom and your old PBX each speak their own dialect of SIP. The SBC rewrites headers and remaps codecs as each call passes through, so calls go through instead of failing with errors your team has to chase.
No Surprise International Bills
Your carrier, Teams, Zoom and your old PBX each speak their own dialect of SIP. The SBC rewrites headers and remaps codecs as each call passes through, so calls go through instead of failing with errors your team has to chase.
An Internal Network Outsiders Can't See
Outsiders only ever see the SBC (this is called topology hiding). Your PBX addresses, extensions, and server names never leave your network, so attackers have nothing to map.
Clear Calls Even at Peak Hour
Your SBC caps how many calls each trunk, site, and user can run at once. Call quality stays clear when the network is busy, and one hijacked account can't tie up all your lines.
Conversations No One Can Overhear
TLS locks down call setup, and SRTP encrypts the audio itself. Microsoft Teams Direct Routing and Zoom Phone BYOC both require this encryption before they will carry your calls.
Calling Working Through an Outage
A second SBC and a second carrier trunk take over automatically if the main path fails. Self-bought deployments often drop this to save money. Capstar includes it in the design wherever your business needs it.
One managed point between your carrier and your platforms
- SecurityTLS and SRTP encryption, topology hiding, fraud blocking
- InteroperabilitySmooths out each carrier's version of SIP
- InterworkingRemaps codecs and headers between systems
- QoS assuranceAdmission control keeps every call clear
- Session routingSends each call to Teams, Zoom or your PBX
Subscribe, Don’t Buy
Why Buy an SBC When You Can Subscribe to One?
With SBC as a Service, Capstar Solutions owns and runs the session border controller, and you subscribe to the capacity you need. You get the same certified connection to Microsoft Teams, Zoom Phone, or your PBX, without the upfront purchase, the license stack, or needing SIP skills in-house. Pick the model that fits your IT policy:
Fully hosted
Runs in Capstar’s environment. Nothing to install on your premises.
On Your Premises
Installed at your site and managed remotely by Capstar Solutions
Co-Managed
Capstar runs it day to day, and your team keeps admin access.
What’s Included?
What’s Included in SBC as a Service Pakistan from Capstar Solutions
Every Capstar Solutions SBC as a Service subscription covers the platform, the configuration, and the ongoing operation. What changes between customers is scale: the number of channels, sites, and platforms the SBC connects.
Fully Managed, Hosted SBC
Capstar Solutions provisions and runs the session border controller. Your team does not install, configure or maintain it.
On-premise PBX Interconnect
SIP trunking and PSTN connection for an existing Sangoma IP PBX, Avaya, or other platform, including side-by-side running during migration.
Regulatory Ccompliance Support
Routing and numbering set up with your licensed carrier in line with Pakistan's telecom regulations and compliance requirements
Microsoft Teams Direct Routing
Secure SIP trunk interoperability between your carrier and Microsoft Teams, including certificates, routing, and number assignment.
Multi-site Central Management
One managed SBC policy for head office and every branch, so each site follows the same routing, security and dial rules.
A Subscription that Scales
Increase or reduce channel capacity as your business grows, consolidates or moves sites, with no large upfront hardware purchase.
Zoom Phone and Contact Center
Bring your own carrier to Zoom Phone, including Zoom Contact Center with Zoom Phone enabled, through a Zoom-certified SBC.
Voice Security Functions
Protection against toll fraud, eavesdropping and denial-of-service attacks, plus topology hiding that keeps your internal network invisible.
Proven Ribbon and AudioCodes platforms
The service runs on the same Ribbon SBCs and AudioCodes SBCs Capstar deploys on-premise, not an unproven platform.
Microsoft Teams & Zoom
Microsoft Teams Direct Routing SBC and Zoom SIP Trunking Security
Microsoft and Zoom both let you keep your own Pakistani carrier, and both require a certified session border controller to do it. Capstar Solutions provides and manages that SBC on either platform, or on both at once.
Microsoft Teams Direct Routing SBC
Direct Routing turns Microsoft Teams into your company phone system while your calls stay on your existing carrier. Microsoft requires a supported, customer-provided SBC in the middle, and Capstar Solutions supplies it as a managed service.
- Signaling: SIP over TLS on port 5061 to Microsoft's endpoints
- Media: Encrypted SRTP between the SBC and Teams
- Certificate: Publicly trusted, matching the SBC's name in a domain verified in your Microsoft 365 tenant
Zoom Phone with your Own Carrier
Zoom Phone's bring-your-own-carrier option lets you keep local carrier rates and numbers. Zoom requires an SBC from its certified vendor list, and Capstar Solutions configures, secures and monitors it for you.|
- SBC: From Zoom's certified vendor list; AudioCodes and Ribbon both qualify
- Certificate: The SBC's fully qualified domain name in the certificate's CN or SAN field
- Firewall: Zoom media allowed across UDP 10000 - 64000
Use Cases
Why Get Your Managed SBC from Capstar Solutions?
Choosing a managed SBC Pakistan-wide comes down to one question: who answers when a trunk drops on a Monday morning? Capstar Solutions is a unified communications integrator, not a box reseller. The same team designs your voice platform, connects the carrier, configures Microsoft Teams or Zoom, and then operates the SBC for as long as you subscribe.
Consultation and Sizing First
Capstar Solutions reviews your call volumes, sites, carrier contracts and platforms before recommending channel capacity, so you do not pay for more than you use.
Ribbon and AudioCodes Expertise
Fully Managed and Hosted
Provisioning, configuration, firmware, certificates, monitoring and changes are all handled by Capstar Solutions engineers under one agreement.
Microsoft Teams and Zoom Experience
Capstar Solutions delivers Microsoft Teams Direct Routing and Zoom Phone projects, so the SBC and the cloud platform are configured by the same people.
Deployment & Support
How Capstar Solutions Deploys and Supports Your SBC
Capstar Solutions onboards SBC as a Service Pakistan customers in six stages, from sizing to ongoing operation. The timeline mostly depends on your carrier and the number of sites, and you receive a dated plan after the assessment.
Needs Assessment and Sizing
Capstar Solutions reviews your call volumes, sites, current phone system, and carrier contracts, then recommends channel capacity and a redundancy design.
Microsoft Teams and Zoom Configuration
Capstar configures Direct Routing or Zoom Phone, assigns numbers, tests calls in both directions and runs any legacy PBX side by side until cutover.
Regulatory Compliance Support
We keep routing and numbering aligned with your carrier and Pakistan's telecom regulations as your setup changes.
SBC Provisioning and Onboarding
Capstar provisions the managed SBC, issues certificates and connects your carrier's SIP trunk, coordinating directly with the carrier.
Ongoing Monitoring and Security Management
Capstar Solutions watches call quality and capacity, applies firmware updates, renews certificates and tunes fraud and denial-of-service policies.
Subscription Scaling
As your business grows or consolidates, Capstar adjusts capacity, adds sites, or connects new platforms without new hardware.
Who Uses It
Industries Using SBC as a Service in Pakistan
If your carrier trunk connects to a cloud calling platform, you need an SBC. These are the sectors where Capstar Solutions delivers it most, and what each one gets out of it.
Corporate Offices
Move your head office from an on-premises PBX to Microsoft Teams calling while keeping your carrier trunk and every number intact.
Healthcare
Keep analogue handsets and paging running alongside modern cloud calling, so departments move over gradually instead of in one risky cutover.
BPOs and Call Centers
Scale channel capacity up or down for each campaign, and add an omnichannel contact center platform whenever you need one.
Education
Connect every campus and extension through one managed SBC, with capacity that stretches for admissions and exam-season peaks.
Banks and Financial Services
Get the call encryption, topology hiding and auditable call control your procurement and compliance teams require, for an operation where downtime is not an option.
Government and Public Sector
Keep tight control over where voice traffic goes and who can reach your internal network, with the SBC as your controlled entry point.
Request a Consultation
Tell Us About Your Voice Setup
Share a few details and a Capstar Solutions engineer will come back within one business day with a sizing recommendation and a quote.
Request a Quote
The more detail you share, the more accurate our proposal.
FAQs
SBC as a Service: Frequently Asked Questions
Straight answers to the questions IT directors and managers in Pakistan ask before choosing a managed SBC.
What is SBC as a Service?
SBC as a Service is a subscription to a session border controller that a provider owns and operates for you. Capstar Solutions hosts, configures, secures and monitors the SBC that connects your SIP trunk to Microsoft Teams, Zoom Phone or an on-premise PBX. You get the same interoperability and call security as a purchased SBC, without buying hardware or licences, and capacity scales up or down with your business.
Do I need an SBC for Microsoft Teams Direct Routing?
Yes. Microsoft requires a supported, customer-provided session border controller for every Direct Routing deployment. The SBC connects your carrier trunk to Microsoft over SIP/TLS on port 5061 and needs a publicly trusted certificate in a domain verified in your Microsoft 365 tenant. Microsoft Calling Plans and Operator Connect do not need your own SBC, but Direct Routing is the option that lets you keep an existing Pakistani carrier contract. Capstar Solutions supplies the Direct Routing SBC as a managed service.
Does Zoom Phone need an SBC to use my own carrier?
Yes. Zoom Phone’s bring-your-own-carrier option requires a session border controller from Zoom’s certified vendor list between your carrier and Zoom. The SBC’s domain name must appear in its certificate, and your firewall must allow Zoom media on UDP ports 10000 to 64000. Capstar Solutions configures and manages the Zoom SBC on AudioCodes or Ribbon, coordinates the trunk with your carrier and keeps your numbers working through the move.
Is SBC as a Service cheaper than buying an SBC?
SBC as a Service removes the upfront cost of buying an SBC: the appliance, channel licences, a standby unit for failover and the engineering time to configure and maintain them. You pay a recurring subscription instead. Whether it costs less over several years depends on your channel count, number of sites and redundancy needs. Capstar Solutions does not publish list prices, so request a quote for an itemised comparison.
Can a managed SBC connect my existing PBX to Microsoft Teams or Zoom?
Yes. A managed SBC sits between an existing Sangoma, Avaya or other PBX and Microsoft Teams or Zoom, so both systems can call each other during a migration. That lets you move users in stages instead of in a single weekend cutover. Where analogue or E1 lines are involved, Capstar Solutions pairs the SBC with a VoIP gateway to connect them.
How does an SBC protect against toll fraud and eavesdropping?
A session border controller encrypts call signalling with TLS and call audio with SRTP, so conversations cannot be intercepted. It hides your internal network addresses, rate-limits and blocks attack traffic, and caps concurrent calls so a compromised account cannot place hundreds of international calls. With SBC as a Service, Capstar Solutions sets these policies during onboarding and monitors them continuously.
Can one managed SBC serve several branch offices?
Yes. A centrally managed SBC can carry calls for a head office and many branches under one routing and security policy, which suits banks, retail chains and multi-campus universities. Capstar Solutions designs the capacity and failover for all sites together, then adds new locations to the same subscription as you open them.
What does SBC as a Service cost compared to buying SBC hardware?
Buying an SBC is a capital purchase: the appliance, channel and feature licences, a second unit for high availability, plus rack space, power and engineering time. SBC as a Service turns that into a recurring operating cost for the channel capacity you actually use, with the hardware and licensing absorbed by the provider. It is usually the better choice when you have no in-house SIP engineer, a single Teams or Zoom project, or seasonal call volume. Capstar Solutions quotes every deployment individually, because the price depends on channel count, redundancy and number of sites. For Zoom Phone BYOC, your quote lists Zoom licences, your carrier’s call charges and the SBC separately, so you can see exactly what drives the total.
Which SBC vendors does Capstar Solutions deploy in Pakistan?
Capstar Solutions deploys AudioCodes and Ribbon Communications session border controllers. Both are certified by Microsoft for Teams Direct Routing and appear on Zoom’s certified list for Phone BYOC, so your deployment stays fully covered by vendor support whichever you choose. Capstar recommends one or the other based on your channel count, whether you need on-premises hardware or a virtual SBC, your redundancy needs and the platform you are connecting to, so you get the platform that fits your setup, not a one-size-fits-all box.
Can an SBC connect my existing PBX to Microsoft Teams or Zoom?
Yes, and it is one of the most common reasons Pakistani enterprises choose one. A session border controller sits between your existing PBX and the cloud platform and translates SIP between them, so both run at the same time and users on either system can call each other. You migrate in stages instead of risking one cutover weekend, which matters when you have hundreds of extensions, analogue devices or a contact center that can’t go offline. Where analogue or E1 PRI circuits are involved, Capstar Solutions pairs the SBC with a VoIP gateway to terminate those lines.
How long does an SBC as a Service deployment take in Pakistan?
The SBC configuration is usually the quickest part. Your schedule depends on four outside factors: how fast your carrier delivers or re-points the SIP trunk, whether numbers need porting, how long certificate issuance and DNS changes take, and whether you need one site or several with failover. A single-site Teams Direct Routing or Zoom Phone BYOC connection moves considerably faster than a multi-site rollout with number porting and legacy PBX interconnect. Capstar Solutions gives you a dated project plan after the needs assessment instead of a generic estimate, so the dates you plan around are ones we can actually meet.
Related Solutions from Capstar Solutions
AudioCodes SBCs
The AudioCodes Mediant platform Capstar deploys for Teams Direct Routing and Zoom Phone.
Ribbon SBCs
Ribbon session border controllers for Microsoft Teams, Zoom, and contact center voice.
Microsoft Teams Direct Routing
Bring PSTN calling into Teams using the SBC this service provides and manages.
Zoom Phone
Cloud telephony on Zoom, with BYOC connectivity to your existing Pakistani carrier.