Grandstream UCM6300 vs UCM6300A Series: Which IP PBX Should You Choose?
Compare the Grandstream UCM6300 and UCM6300 Audio Series by users, concurrent calls, analog ports, video collaboration, call recording, remote work and growth requirements. Then use the model selector to identify a practical starting point for your deployment.
Which Grandstream UCM6300 model should you choose?
Choose the standard UCM6300 Series when video meetings and higher maximum scale are important. The standard family ranges from the UCM6301 to UCM6308 and supports up to 3,000 users and up to 450 concurrent G.711 calls depending on model. Choose the UCM6300 Audio Series when your deployment is primarily voice, messaging, audio meetings and call routing. The Audio family ranges from UCM6300A to UCM6308A and supports up to 1,500 users and up to 200 concurrent G.711 calls depending on model.
Do not size an IP PBX only by extension count. Concurrent calls, SIP or analog trunk requirements, call recording, SRTP usage, conferencing, branch architecture and expected growth can change the correct choice.
Grandstream UCM6300 vs UCM6300A: What is the difference?
The “A” in UCM6300A identifies Grandstream's Audio Series. Both families provide an on premises IP PBX platform with Wave, call routing, IVR, queues, recording, APIs and remote connectivity options, but their capacity and collaboration focus differ.
UCM6301 · UCM6302 · UCM6304 · UCM6308
Best suited when organizations want voice plus built in video collaboration capability and the larger models are needed for higher user and concurrent call capacity.
- Up to 3,000 users by model
- Up to 450 concurrent G.711 calls by model
- Built in video conferencing capability
- Wave desktop, web and mobile access
- API integration, GDMS and UCM RemoteConnect ecosystem support
UCM6300A · UCM6302A · UCM6304A · UCM6308A
Best suited to voice focused deployments where telephony, call queues, IVR, messaging, audio meetings and remote extensions are the primary requirements.
- Up to 1,500 users by model
- Up to 200 concurrent G.711 calls by model
- Voice and audio collaboration focus
- Wave desktop, web and mobile access
- API integration, GDMS and UCM RemoteConnect ecosystem support
UCM6300 and UCM6300A model comparison
The following figures are based on Grandstream's current published specifications. Capacity represents platform maximums under the stated conditions and should not be treated as a substitute for project sizing.
Standard UCM6300 Series
| Model | Maximum users | Concurrent G.711 calls | Concurrent SRTP calls | FXS ports | FXO ports |
|---|---|---|---|---|---|
| UCM6301 | 500 | 75 | 50 | 1 | 1 |
| UCM6302 | 1,000 | 150 | 100 | 2 | 2 |
| UCM6304 | 2,000 | 300 | 200 | 4 | 4 |
| UCM6308 | 3,000 | 450 | 300 | 8 | 8 |
UCM6300 Audio Series
| Model | Maximum users | Concurrent G.711 calls | Concurrent SRTP calls | FXS ports | FXO ports |
|---|---|---|---|---|---|
| UCM6300A | 250 | 50 | 50 | 0 | 0 |
| UCM6302A | 500 | 75 | 75 | 2 | 2 |
| UCM6304A | 1,000 | 150 | 120 | 4 | 4 |
| UCM6308A | 1,500 | 200 | 150 | 8 | 8 |
Source: Grandstream UCM6300 Series and UCM6300 Audio Series datasheets. Always verify firmware specific limits and project requirements before procurement.
Find your starting UCM model
Answer six practical questions. This tool gives a preliminary family and model suggestion. A final design should still validate simultaneous call traffic, trunking, recording storage, network design, availability requirements and future growth.
How to size a Grandstream UCM correctly
User count is only the first filter. In real deployments, the busiest hour, encrypted call load, recording policy, trunks, conferencing and resilience requirements are often more important than the total number of extensions.
Count registered users
Include desk phones, softphones, remote users, common area phones, conference phones and future extensions.
Estimate concurrency
Size for the maximum simultaneous internal and external calls during your busiest operational period, not the daily average.
Define trunk architecture
Identify SIP trunks, PSTN lines, GSM gateways and any existing PBX interconnection that must remain in service.
Plan recording
Decide who must be recorded, retention duration, expected call minutes, storage destination, backup and authorized access.
Check collaboration needs
If built in video meetings matter, the standard UCM6300 family is usually the logical family to evaluate first.
Leave growth headroom
A design that is already near a platform limit on day one leaves little room for seasonal peaks, new branches or future applications.
Which UCM for 25, 50, 100, 250, 500 or 1,000 users?
| Typical scale | Practical starting point | Why |
|---|---|---|
| Up to 50 users | UCM6300A or UCM6301 | Choose family according to voice only versus video collaboration requirements. Validate concurrency and analog ports. |
| 50 to 250 users | UCM6300A, UCM6302A, UCM6301 or UCM6302 | Traffic profile can matter more than user count. Use the larger option when concurrency, recording or growth demands it. |
| 250 to 500 users | UCM6302A or UCM6301/UCM6302 | Both families can serve this range, but family choice depends on collaboration requirements and call load. |
| 500 to 1,000 users | UCM6304A or UCM6302/UCM6304 | Validate simultaneous calls, SRTP, queues and expected expansion carefully. |
| 1,000 to 1,500 users | UCM6308A or UCM6304/UCM6308 | The Audio family tops out at 1,500 users. Standard models provide greater headroom if growth is likely. |
| Above 1,500 users | UCM6304 or UCM6308 | Standard UCM6300 models support the higher scale, subject to all other capacity limits. |
Which Grandstream UCM model fits which deployment?
UCM6300A
- 250 users
- 50 concurrent G.711 calls
- No built in FXS or FXO ports
- Voice focused small business deployments
UCM6302A
- 500 users
- 75 concurrent G.711 calls
- 2 FXS + 2 FXO ports
- Good fit for many SME voice deployments
UCM6304A
- 1,000 users
- 150 concurrent G.711 calls
- 4 FXS + 4 FXO ports
- Higher call traffic and larger sites
UCM6308A
- 1,500 users
- 200 concurrent G.711 calls
- 8 FXS + 8 FXO ports
- Large voice centric deployments
UCM6301
- 500 users
- 75 concurrent G.711 calls
- 1 FXS + 1 FXO port
- Small to medium unified communications
UCM6302
- 1,000 users
- 150 concurrent G.711 calls
- 2 FXS + 2 FXO ports
- Growing organizations and higher concurrency
UCM6304
- 2,000 users
- 300 concurrent G.711 calls
- 4 FXS + 4 FXO ports
- Large organizations and campuses
UCM6308
- 3,000 users
- 450 concurrent G.711 calls
- 8 FXS + 8 FXO ports
- Large and high traffic deployments
Which UCM is best for different organizations?
Corporate office
Choose according to employee count and call concurrency. If Teams or another video platform already handles meetings, an Audio Series model may cover telephony efficiently.
Call centre
Concurrency, queue traffic, recording load, reporting expectations and supervisor requirements matter more than simple extension count. For deeper omnichannel and contact centre workflows, also compare 3CX.
Banking and financial services
Recording retention, access control, resilience, branch connectivity and regulatory requirements should be defined before hardware selection. A larger model can be justified by concurrency or availability even with fewer users.
Hospital and healthcare
Separate administrative, clinical, reception, paging and emergency workflows. Consider analog devices, call recording policy, after hours routing and failover.
Hotel and hospitality
Guest room analog devices, PMS integration, front desk call flows and large extension counts can make gateway capacity and third party integration especially important.
School, university or campus
Plan for classrooms, administration, security, reception, paging and multiple buildings. Standard UCM6300 models can be attractive where video collaboration is also required.
Manufacturing
Include offices, production floors, warehouses, guard rooms, paging, cordless mobility and any legacy analog equipment that must remain connected.
Multi branch business
Centralized versus distributed design should be decided before model selection. WAN quality, local survivability, SIP trunks and intersite dialing influence the architecture.
CRM driven sales team
API and telephony integration requirements may drive the choice. TekkPak can integrate compatible Grandstream deployments with CRM workflows including Odoo.
Does call recording change the UCM model you should buy?
It can. Recording every call creates storage, retention, backup and access requirements that should be designed before procurement. The number of recorded conversations, average call duration, retention period and selected storage method can be more important than the PBX's raw user capacity.
For regulated or high volume environments, treat recording as a system design workstream rather than a checkbox. Define who is recorded, where files are stored, how long they are kept, who can access them and how backups are protected.
Recording sizing checklist
- How many users or trunks are recorded?
- What are the average recorded minutes per day?
- How many days, months or years must recordings be retained?
- Will recordings remain local or be copied to external storage?
- What backup and disaster recovery policy applies?
- Which users may search, play, download or delete recordings?
- Are encrypted calls and security controls required?
Which UCM should you choose for multiple branches?
For a multi site business, the first decision is architectural: one centralized PBX, a PBX at each important site, or a hybrid arrangement. The best model depends on WAN reliability, local survivability, interbranch traffic, SIP trunk topology, call recording, number portability and support requirements.
Centralized UCM
Can simplify administration and dialing plans, but remote sites become more dependent on WAN availability and the central platform.
Distributed UCMs
Can improve site autonomy and survivability while requiring more planning for routing, numbering, management and cross site features.
Hybrid design
Useful when a head office requires central control but critical sites need local calling continuity or separate carrier connectivity.
When should you choose 3CX instead of Grandstream UCM?
A Grandstream UCM is attractive when you want a purpose built on premises communications appliance with integrated telephony features and a strong Grandstream endpoint ecosystem. 3CX can become more attractive when the project is centered on software deployment flexibility, cloud hosting, advanced contact centre workflows, web based users or specific CRM and digital channel requirements.
The correct decision is not “which brand is better?” It is which architecture fits the business requirement, integration roadmap, operational model and total cost.
Compare 3CX vs Grandstream UCMConsider 3CX when...
- Cloud or virtualized deployment is a primary requirement
- Remote and browser based users dominate the environment
- Contact centre and CRM workflows drive the project
- Digital channels and software integrations are strategically important
- You want to separate PBX software from a dedicated hardware appliance
Related Grandstream and 3CX guides from TekkPak
After selecting the platform, use these implementation guides to plan trunks, routing, queues, recording and integrations.
Grandstream Solutions in Pakistan
Explore UCM IP PBX, IP phones, gateways and networking from TekkPak.
Grandstream UCM6300 Setup Guide
Plan the wider UCM configuration workflow from extensions to routing and security.
Configure SIP Trunks on UCM6300
Set up register or peer SIP trunks, routes, DID handling, NAT and codecs.
Configure UCM6300 Call Queues
Set up agents, queue strategy, announcements and operational controls.
Build a Multi Level IVR
Create structured caller journeys with menus, time conditions and fallback routing.
Grandstream UCM6300 Call Recording
Understand recording configuration, policies, storage and operational considerations.
Integrate Odoo with Grandstream UCM6300
Connect compatible telephony and CRM workflows for click to dial and call context.
3CX vs Grandstream UCM
Compare deployment model, integrations, contact centre requirements and control.
Grandstream UCM6300 buyer FAQ
What is the main difference between UCM6300 and UCM6300A?
The UCM6300A models belong to Grandstream's Audio Series and are intended for voice focused unified communications. The standard UCM6300 family adds video collaboration capability and scales higher, reaching up to 3,000 users and 450 concurrent G.711 calls on the UCM6308.
What is the smallest Grandstream UCM6300 Audio model?
The UCM6300A is the entry model in the Audio Series. Grandstream specifies up to 250 users and 50 concurrent G.711 calls. It has no built in FXS or FXO analog ports, so analog phones or PSTN lines require suitable gateways.
How many users can the UCM6302A support?
Grandstream specifies up to 500 users, 75 concurrent G.711 calls and 75 concurrent SRTP calls for the UCM6302A. It also includes two FXS and two FXO ports.
How many users can the UCM6304 support?
The standard UCM6304 supports up to 2,000 users and up to 300 concurrent G.711 calls according to Grandstream's current datasheet. It includes four FXS and four FXO ports.
How many users can the UCM6308 support?
The UCM6308 is the highest capacity model in the standard UCM6300 family, supporting up to 3,000 users and up to 450 concurrent G.711 calls according to the current Grandstream datasheet.
Which Grandstream PBX is suitable for about 100 users?
For 100 users, several UCM models have sufficient user capacity. The correct choice depends mainly on simultaneous calls, whether built in video meetings are needed, analog ports, call recording and growth. A UCM6300A or UCM6301 may be a starting point, but higher traffic can justify a larger model.
Which UCM is best for a call centre?
There is no single model for every call centre. Size according to active agents, peak concurrent calls, queue design, recording load, reporting and future growth. Also compare 3CX if advanced contact centre, CRM or digital channel workflows are central to the project.
Can Grandstream UCM6300 record calls?
Yes. The UCM6300 platform includes call recording capabilities. For large deployments, recording storage, retention, backup and user access should be designed as part of the overall solution.
Can Grandstream UCM6300 integrate with Odoo CRM?
Grandstream provides APIs for third party integration. TekkPak has published a practical guide covering an integration approach between compatible UCM6300 deployments and Odoo CRM, including extension mapping and telephony workflow considerations.
Can TekkPak help select and deploy the correct UCM in Pakistan?
Yes. TekkPak Technologies is a Grandstream Authorized Reseller in Pakistan and can assist with requirement analysis, model sizing, IP phones, gateways, SIP trunks, configuration, call recording, CRM integration, deployment and support.
Technical review and methodology
Prepared as a practical buyer and solution sizing guide by TekkPak Technologies. Product capacities were checked against Grandstream's published UCM6300 and UCM6300 Audio Series documentation. Final project recommendations should be validated against current firmware, call traffic, integrations, security, recording and resilience requirements.
Reviewed: 10 September 2026
Let TekkPak size the Grandstream UCM around your actual call traffic
Tell us your number of users, expected concurrent calls, sites, trunks, analog devices, recording requirements and growth plan. We can recommend the appropriate UCM, IP phones, gateways, storage approach and deployment architecture.
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