A multi channel voice gateway is a VoIP appliance that carries several simultaneous calls between an IP network and the mobile network. Where a single-channel device handles one call at a time, a multi-channel gateway handles many, which is what call centers, VoIP providers, and multi-line offices actually need. The channel count is the gateway’s most important specification: it sets the ceiling for concurrent calls.
Telarvo Store’s multi-channel voice gateways are the SK VoIP Gateway family, spanning 4 to 32 ports. This article explains what channel count means in practice, how the Telarvo models compare, and how to size a multi-channel deployment.
What Channel Count Means on a Voice Gateway
Each channel on a VoIP gateway corresponds to a GSM/LTE module and the ability to carry one call. An 8-port gateway can carry eight calls at the same time; a 32-port gateway can carry 32. When a call arrives and all channels are busy, the call waits in the PBX queue until a channel frees. Channel count therefore directly bounds the concurrency of the voice service.
The channel count is separate from the SIM count. Channels determine how many calls run at once; SIMs determine how many numbers are available for those calls. A multi-channel gateway with a large SIM pool can rotate many numbers across its channels, which is the standard way to keep per-number volume within operator terms.
The Telarvo Multi-Channel Range
Telarvo’s SK VoIP Gateway family covers four channel sizes:
| Model | Ports / SIM slots | Price (USD) |
|---|---|---|
| SK VoIP Gateway 4-4 | 4 / 4 | $260.00 |
| SK VoIP Gateway 8-8 | 8 / 8 | $480.00 |
| SK VoIP Gateway 8-32 | 8 / 32 | $620.00 |
| SK VoIP Gateway 16-16 | 16 / 16 | $899.00 |
| SK VoIP Gateway 16-64 | 16 / 64 | $1,050.00 |
| SK VoIP Gateway 16-128 | 16 / 128 | $1,200.00 |
| SK VoIP Gateway 16-256 | 16 / 256 | $1,450.00 |
| SK VoIP Gateway 16-512 | 16 / 512 | $1,550.00 |
| SK VoIP Gateway 32-32 | 32 / 32 | $1,550.00 |
| SK VoIP Gateway 32-128 | 32 / 128 | $1,850.00 |
| SK VoIP Gateway 32-256 | 32 / 256 | $2,300.00 |
| SK VoIP Gateway 32-512 | 32 / 512 | $2,520.00 |
| SK VoIP Gateway 32E-SIM | 32 / eSIM | $3,100.00 |
All models are 2G/4G and provide GSM-to-VoIP conversion with multi-line support for call centers, SMS services, and enterprise use.
Sizing Channels to the Call Center Floor
The sizing rule for channels is simple: count the maximum simultaneous calls and buy at least that many ports. A four-agent call center can start with the 4-4; an eight-agent floor needs the 8-8 or 8-32; a 20-agent floor needs the 16-port tier or a 32-port unit, depending on how calls cluster. The peak matters more than the average, because an undersized gateway queues calls during the busy hour.
For growth, add headroom rather than replacing hardware. A 20-agent floor on a 16-port gateway runs at 80% capacity in the peak; a 32-port unit gives the same floor 60% headroom for seasonal spikes. The SIM pool is sized separately, based on how many numbers the calling pattern needs.
Multi-Channel Behavior Under Load
When the floor is busy, the gateway’s behavior is governed by its channels and the PBX queue. Calls route to free channels as they become available, and SIM allocation selects a number for each call from the pool. Because the gateway registers over standard SIP, the PBX controls the queue and routing; the gateway provides the channels and the mobile path.
The multi-channel design also supports mixed traffic. A call center that places outbound calls and receives inbound calls through the same gateway uses its channels for both directions, and the PBX dial plan decides which calls route through which channels. The same chassis can carry SMS alongside voice on the SK VoIP Gateway family, which is positioned for call centers, SMS services, and enterprise communications.
Redundancy for Multi-Channel Voice
For production voice, multi-channel should mean multi-unit redundancy. Two 16-port gateways behind a PBX give a 20-agent floor its 32 channels with the ability to shift traffic during maintenance. Because the gateways register over SIP, the PBX routes around a failed unit automatically. The configuration is exported per unit, so a replacement can be restored quickly.
Redundancy planning also covers the SIM side: a shared SIM pool behind two gateways means a failed gateway does not strand its numbers. The pool’s allocation system keeps the inventory usable by whichever gateway needs a line.
Buying and Support
The SK VoIP Gateway models are available on telarvostore.com at the prices above; most models above $620.00 include free shipping. Orders ship within two business days via DHL or FedEx, include a 12-month warranty, and are backed by 7×12 technical support. For a quotation with SIM bundling or a multi-unit deployment, contact sales@telarvo.com.
A Capacity Example for a Growing Office
Run the numbers for a 12-person office that plans to grow to 20. Current peak is 10 simultaneous calls, so the 16-16 at $899.00 covers today with six channels of headroom. The growth plan adds 8–10 more channels, which the 16-port tier absorbs; if the floor passes 24 concurrent calls, the 32-512 becomes the relevant upgrade. The SIM pool starts at 16 and grows with the calling pattern, not with the headcount.
The example shows the two decisions made separately: channels follow the concurrent call peak, and SIMs follow the number requirement. Buying both against the same headcount number is the classic mistake that either overbuys channels or underbuys numbers.
How Multi-Channel Gateways Handle Mixed Traffic
Multi-channel voice gateways are not limited to outbound calling. The same channels carry inbound calls from SIM numbers, and the PBX dial plan decides which direction each channel serves. A call center can advertise local mobile numbers for inbound support while placing outbound calls through the same gateway. The channel is the shared resource; the direction is a routing decision.
The SK VoIP Gateway family also carries SMS alongside voice, which is why Telarvo positions it for call centers, SMS services, and enterprise communications. An operation that already runs the gateway for voice can use its lines for notification SMS and verification codes. This dual use raises the value of each channel, especially for smaller deployments where separate voice and SMS appliances would be underutilized.
Selecting the SIM Pool for a Multi-Channel Gateway
The SIM configuration on a multi-channel gateway determines how many numbers are available for the channels. A simple office can run one SIM per port. An operation that places many calls needs a larger SIM pool so per-number volume stays within operator terms. The Telarvo range makes this choice explicit: the 16-port tier spans the 16-16 through 16-512, and the 32-port tier spans the 32-32 through 32-512.
The selection method is the same at every channel size: estimate the calls per day, divide by the target calls per number, and choose the SIM configuration above the result. For an operator placing 2,000 calls daily at 10 calls per number, the requirement is 200 numbers, which the 16-256 or 32-256 configuration covers. The channel count and SIM count are planned against different measurements.
Security and Network Planning for Multi-Channel Voice
Multi-channel voice gateways should be secured at the network level. The gateway sits behind the office firewall, SIP registration uses credentials, and the management interface is restricted to the operations network. These are standard practices, and Telarvo’s documentation covers the recommended configuration.
Network planning covers bandwidth and power. Each concurrent call uses a modest amount of bandwidth, and the PBX and gateway should be on a network segment that can carry the peak call load without contention. Power planning is simpler: a UPS for the gateway keeps the mobile trunk online during short outages. The 12-month warranty and 7×12 support cover the hardware and setup.
When to Scale from 16 to 32 Channels
The step from 16 to 32 channels is the most common growth path in the Telarvo range. The trigger is the concurrent call peak: when the floor regularly approaches the 16-channel ceiling, calls queue during the busy hour, and the upgrade restores headroom. The migration is a hardware addition rather than a platform change — the new gateway registers to the same PBX, and the dial plan routes traffic across both units.
The upgrade also typically adds SIM capacity. Moving from a 16-128 to a 32-256, for example, adds both channels and numbers, matching the two resources to the grown workload. The same SIP integration and management approach carry over, so the expansion is incremental rather than a rebuild.
Verifying a Multi-Channel Gateway Before Production
Before production traffic, run a verification pass on the multi-channel setup. Confirm each channel registers with the PBX and shows available status, place test calls through several channels to verify completion and audio quality, and check the SIM allocation behavior — which numbers are selected for outbound calls and how they rotate across the pool. If the deployment uses SMS, send a test batch and confirm delivery records.
The verification should also cover the SIM side: balances funded, plans permitting the traffic type, and no single number carrying an unusual share of the test traffic. The checks take part of a day and turn the gateway from a hardware purchase into a known quantity before the first production call.
Frequently Asked Questions
What is a multi channel voice gateway?
It is a VoIP appliance that carries several simultaneous calls between IP and mobile networks, with the channel count bounding concurrent calls.
How many channels do Telarvo gateways offer?
The SK VoIP Gateway family covers 4, 8, 16, and 32 ports, with SIM capacities from 4 to 512 plus an eSIM model.
How do I size the channel count?
Count the maximum simultaneous calls at the peak and buy at least that many ports, with headroom for growth and seasonal spikes.
Can a multi-channel gateway handle inbound and outbound calls?
Yes. The PBX dial plan routes both directions through the gateway’s channels, and the same chassis can also carry SMS.
What warranty and support are included?
A 12-month warranty, 7×12 technical support, and worldwide shipping within two business days.