From Keyphone Systems to IP: Why the Transition Makes Economic Sense
Many Singapore offices are still running keyphone systems: Panasonic KX-T series, NEC, or similar hybrid PBX units installed years ago. These systems work, but they are becoming harder to support, their capabilities are fixed, and the cost model of PSTN lines has been superseded by SIP trunks that deliver more capacity at lower cost. When a keyphone system develops a fault, the question is no longer just whether to repair it: it is whether the repair cost is better spent on a transition to an IP system that will serve the office for the next decade.
The economics are straightforward. A two-line PSTN subscription from a Singapore telco costs more monthly than a SIP trunk account that provides five concurrent call channels on a single subscription: more capacity, more numbers, more features, at a lower cost. The IPPBX hardware pays for itself in a short time relative to the ongoing savings. Yeastar is the platform Securevision specifies for this transition: a mature, well-supported, feature-rich IPPBX that handles everything from a five-person office to a 500-person enterprise, with a clear upgrade path between models.
Securevision Scope
Securevision supplies, installs, and configures Yeastar P-Series and S-Series IPPBX systems for Singapore offices. We handle SIP trunk provisioning with Singapore telcos, IP phone provisioning (Fanvil, Yealink), Linkus mobile app setup, IVR programming, call routing, and ongoing support. For offices transitioning from an existing PSTN or keyphone system, we manage the migration so the office maintains telephony continuity throughout.
Five Things an IP Phone System Does That a Keyphone Cannot
DID Numbers: Every Person Gets Their Own Direct Line
On a traditional keyphone system, outgoing calls show the company's main number. When someone calls back, they reach the operator or receptionist and have to be transferred. The person who made the original call is anonymous from the outside world's perspective.
With a Yeastar IPPBX on a SIP trunk with DID (Direct Inward Dialling), every extension can be assigned its own unique Singapore number. When a salesperson calls a client from extension 201, the client sees a specific number: say, 6XXX 0201. When the client calls back on that number, it rings directly to that salesperson without going through the operator. Singapore telcos offer DID numbers in blocks of 10 at competitive rates, making it affordable to give every staff member a direct number. This is a significant change in how an office appears externally and how efficiently incoming calls are handled.
Linkus: Your Mobile Phone Becomes Your Office Phone
Yeastar's Linkus app turns a smartphone or laptop into a full IPPBX extension. When someone calls the staff member's office extension, it rings simultaneously on their desk phone and on Linkus on their mobile. They can answer on either device. When they make an outgoing call through Linkus, the recipient sees the office number: not the personal mobile number.
For Singapore offices where staff are frequently out of the office, driving between sites, or working from home, Linkus means they are reachable on their office number wherever they are. International roaming is particularly compelling: a staff member in Japan or London can make and receive calls as though they are at their Singapore desk: outgoing calls to Singapore numbers use the SIP trunk and incur no international charges. For security companies with guards deployed across multiple sites, Linkus means every guard is reachable on an office extension without the company paying for individual mobile lines.
Flexible Call Routing: Time-Based, Group, and Forward
A Yeastar IPPBX handles call routing programmatically: not by physically rewiring anything. During office hours, incoming calls to the main number go to reception. After 6pm, the same number routes to a ring group of managers on Linkus. On public holidays, it routes to a voicemail with a custom message. A staff member going on leave can forward their direct number to a colleague for the duration, and revert it when they return: all through the management interface.
For businesses with multiple offices in Singapore or across countries, all locations connect through the same Yeastar system over the internet. A call from the Jurong office to the Tampines office is an internal extension call: free, instant, and indistinguishable from calling the next desk. Overseas offices connect the same way: a staff member in Kuala Lumpur calls the Singapore office on an extension, and the Singapore office calls Malaysia as an internal extension at zero cost.
IVR, Voicemail, and Call Recording: Built In
Interactive Voice Response (IVR): the system that answers with "press 1 for Sales, press 2 for Support": is built into Yeastar at no additional cost. Recording a custom greeting, building a menu, routing to ring groups or individual extensions, and setting different routing for different times of day are all standard configuration tasks in the Yeastar management interface.
Voicemail with email delivery: missed calls go to voicemail and the audio file is emailed to the extension user: is standard. Call recording for compliance or training purposes is available on P-Series models. The P-Series also includes a call centre module with agent queues, wallboards, and supervisor monitoring: relevant for security companies managing guard deployments and for businesses with customer service functions.
SIP Trunk Economics: More Calls for Less Cost
A Singapore PSTN line subscription provides one simultaneous call channel. Two lines give two simultaneous calls: one incoming, one outgoing, maximum. A SingTel SIP trunk account provides multiple concurrent call channels on a single subscription. A SIP-5 account, for example, allows up to five simultaneous calls: all at once, in any combination of incoming and outgoing.
The monthly cost of a SIP account with five concurrent channels is typically less than the equivalent number of PSTN lines. For a growing Singapore office that regularly finds its lines busy during peak hours, the SIP trunk upgrade simultaneously reduces the monthly telco spend and eliminates the busy-signal problem. DID numbers: one per staff member: can be added in blocks of ten at a variable monthly cost, giving every person a direct number for the price of a minor line rental addition.
SECURE™ Integration
Fanvil door stations register on the Yeastar IPPBX as SIP extensions: visitor calls ring the reception IP phone, with video on Fanvil X7 and X5U colour-display phones. For security guard companies, Yeastar extensions on Linkus give every guard a reachable office extension on their mobile, eliminating the need for separate guard communication lines at each site.
Yeastar Products We Deploy in Singapore
Two product series cover the full range of Singapore office requirements: from a five-person startup to a 500-person enterprise.
S-Series: Entry Level with Analogue Line Support
The S-Series IPPBX is modular and supports FXO ports: allowing connection of existing analogue PSTN lines. For offices not yet ready to commit to a full SIP trunk, the S-Series can run on existing PSTN lines while delivering full IPPBX features internally. The S20 handles up to 20 users; the S50 handles 50. Upgrade path to P-Series as requirements grow.
P-Series: Full Unified Communications
Yeastar's flagship platform: voice, video, Linkus UC app, call centre, CRM integration, call recording, IVR, and operator panel in one system. P550 for up to 50 users (25 concurrent calls). P560 up to 200 users (60 concurrent calls). P570 up to 500 users (120 concurrent calls). All P-Series models include hardware disk for call recording storage.
Cloud Edition: No Hardware Required
Yeastar Cloud PBX is fully hosted: the IPPBX runs in Yeastar's cloud with no on-site hardware beyond the IP phones. Full P-Series features available on a subscription basis. Ideal for offices that want the full Yeastar feature set without managing physical hardware, or for businesses with multiple locations that want a single cloud-hosted IPPBX connecting all sites.
Still on Analogue PSTN Lines? The S-Series Bridge Approach
Some Singapore offices are not ready to switch to SIP trunks: the telco contract has time remaining, or the decision-maker wants to evaluate IP telephony before committing to the full change. The Yeastar S-Series with FXO modules allows exactly this: plug your existing analogue PSTN lines into the S-Series FXO ports, and the IPPBX takes over the management and routing of calls on those lines.
Internally, the office has all the features of an IPPBX: DID numbers, Linkus mobile app, IVR, voicemail, call routing, extension calling between sites. Externally, incoming calls still arrive on the existing PSTN lines and outgoing calls still use those lines. When the PSTN contract ends, the migration to SIP trunk is a configuration change: no hardware replacement required. The S-Series becomes the permanent platform, or upgrades to a P-Series as the business grows.
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