Telesis PX24 IP PBX Business Phone System
Design and manufacture IP PBX Business Phone System, Switching System, VoIP Gateway, and Signaling Converter  

PX24N (Nano): Revolutionary IP PBX

Perhaps, it is the first time in the world!

PX24N is now with increased capacity!

PX24N (Telesis Nano) is a next-generation IP PBX to home and small business market. It is designed to fit the expectations of the market now and in the future. Although most small IP PBX products miss on features, the PX24N differs. The PX24N has many features, which can be built onto large IP PBX systems only or even not.

PX24N IP PBX formula

Formula is simple but attractive like the PX24N itself.

4 analog DC loop trunks (FXO ports), 8 analog subscribers (FXS ports), and 32 IP (SIP, or H.323, or xSIP) users (local or remote, subscriber or trunk) are located in a unique box, featuring an executive digital phone too.

The PX24N IP PBX image

The photo above is not only an executive telephone set but much more inside!...

The PX24N is intuitive and easy to install and can be up in minutes only. The sleek box design and revolutionary features make it an ideal communications platform for today`s dynamic businesses and home users as well.

The PX24N is a complete solution in the same box, which also features an executive digital telephone offering advanced telephony tasks.

The PX24N bottom view

FXS, FXO, power, headset, microphone, handset connectors are located at the bottom.


The PX24N different views

10/100 BaseT ethernet  at the bottom provides VoIP, API, maintenance, billing connectivity.

Easy installation without any special tools, easy administration and easy maintenance make the PX24N an ideal choice for experts as well as novices, who look for a SoHo platform. The PX24N eliminates additional hardware costs and recurring expenses.

The PX24N is a converged communications system with TDM and IP connectivity at the same time. It provides FXS, SIP, xSIP, H.323 for the local connectivity. Standard SIP  and H.323 make the PX24N fully compatible with all industry standard IP devices including IP voice and video phones. Consequently, it is possible to use a mixture of legacy TDM and IP based terminals like phones in the same system. Furthermore, the PX24N offers similar features and services to both TDM and IP users, that make the life easier.

Similar to local connectivity, either provider or inter-office networking is achieved with FXO, SIP and H.323 interfacing. The PX24N can register to multiple TDM or VoIP providers at the same time. This results in flexibility for multi-path and multi-provider access applications. Enhanced routing algorithms allow least cost routing, as well as alternate routing, for the same or different destinations automatically.


The PX24N schema

The PX24N is a converged communications system with TDM and IP connectivity at the same time.

The PX24N also hosts Telesis WebPhone, which is a SIP softphone or client applet. The applet can be run from any Java enabled web browser. Consequently, the embedded feature phone or any other TDM or IP terminal can be accessed wherever is an access to the Internet. That means free calls to your home or office throught the world. A web browser, a microphone, and a headset are sufficient to make calls towards the PX24N and its terminals.

There are more!..

A 100 hours (6000 minutes) capacity DVR (Digital Voice Recorder) exist in each PX24N. DVR brings personal conversation recording capability, voice mail (VMail) services, automatic call distribution and answering machine functions without any expense.

The PX24N supports Telesis developed xSIP (eXtended SIP) protocol too. xSIP makes some value-added services (like busy diplay panel) in the PX24N to be applicable for VoIP calls too. Presently, Telesis offers two products with xSIP protocol. One is the ITS821 IP Phone, and another is freeware XPhone IP Softphone (PC and modile phone editions).

The PX24N supports Telesis developed Xymphony-API protocol too. The result is various telephony tasks such as dialing, call transfer, call park, call retrieve, conference, conversation recording, and display of port status with using a computer. Moreover, Xymphony-API client utility (software) Telesis XCom is a freeware utility.

Standard and Optional Features

Each PX24N comes with the following standard hardware and software features

  • 4 analog DC loop trunks (i.e., CO trunks or FXO ports)
  • 8 analog subscribers (FXS ports)
  • Caller ID encoders (transmitters) for all FXS ports
  • Caller ID decoders (receivers) for all FXO ports
  • 32 SIP, or H.323, or xSIP local users or trunks
  • 2 VoIP-TDM gateway channels
  • One channel Telesis WebPhone
  • DTMF transceivers
  • Conference hardware
  • Integrated CMDR (call records) buffer
  • Integrated DVR (digital voice recorder) with 100 hours (6000 minutes) capacity
  • 4 playing and 4 recording channels for the DVR
  • Personal conversation recording capability
  • Integrated Voice Mail (VMail)
  • Integrated Automatic Call Distributor
  • Integrated Web server for Web based management
  • SNMP (simple network management protocol) support for management
  • Integrated API server
  • Xymphony TSP for Windows TAPI
  • Data link for adjunct call processing servers
  • XDP (Xymphony Discovery Protocol) support
  • Mains power adapter 
  • Hundreds of supplementary services for analog, digital and VoIP users
  • Integrated feature phone with the following capabilities and features 
    • 4.3 inch TFT LCD color display
    • 64 keys in total
    • 4x3 keypad
    • navigation keys
    • call park keys
    • call record key
    • call transfer key
    • volume control keys 
    • shift function key
    • 30 quick access keys (120 quick access with using the Shift key)
    • redial key
    • transfer key
    • disconnect key
    • conference key
    • speakerphone key
    • mute key
    • flash key
    • function keys
    • text keypad 
    • headphone jack
    • microphone jack
    • missed calls listing
    • dialed numbers listing
    • incoming calls listing
    • phone directory
    • playing, deleting voice messages and recorded conversations
    • polyphonic ring melodies
    • ringer melody selection
    • setting call forward unconditional
    • setting call forward busy
    • setting call forward no-reply
    • setting hotline
    • activating call waiting
    • activating do not disturb
    • activating wake-up (reminder) service
    • deflecting calls
    • activating call back
    • holding calls on
    • retrieving calls
    • transferring calls
    • tracing transferred calls (up to 4 calls)
    • activating conference
    • recording the conversation bi-directionally (both calling and called party voices)

PX24N also provides the following options with licensing

  • additional channels for WebPhone
  • xSIP users
  • automatic conversation recording on TDM and IP users
  • AES 256 media encryption for VoIP calls

Technical Specifications



Operational software

Xymphony PX24N r6               

Maintenance and administration

Over IP (web and/or SNMP and/or proprietary)

Operating voltage

220 VAC

CPU Type

High Speed DSPs            

Switching Matrix

Analog subscriber (FXS) loop impedance 1200 ohms

Ethernet interface

10/100 BaseT
Integrated Digital Voice Recorder (DVR) Yes
Integrated CMDR buffer Yes
Integrated Xymphony API Server Yes
Integrated Automatic Call Distributor (ACD) Yes
Integrated Voice Mail Server Yes
Integrated ETSI FSK modem Yes
Integrated Conference Server Yes
Integrated WEB Server Yes

Integrated H.323 Gatekeeper

Integrated SIP Registrar Yes
Integrated xSIP Registrar Yes
Integrated FTP Client Yes



Legacy PBX

Pure IP PBX Yes

Hybrid IP PBX




Analog subscribers (FXS)


Digital subscriber ( PX24N itself)


Analog DC loop trunks (FXO)


SIP users

32 independently programmable SIP users (local or remote, subsriber or trunk)

H.323 users

32 independently programmable H323 users (local or remote, subscriber or trunk)
Telesis xSIP users 32 (1 by default, more with licensing)
VoIP - TDM gateway channels 2
Telesis WebPhone 1 by default, more with licensing
Xymphony-API clients unlimited
DVR (Digital Voice Recorder) recording capacity 100 hours (6000 minutes)
DVR recording channels 4
DVR playing channels 4
DTMF transceivers non-blocking
Caller ID transmitters non-blocking
Caller ID receivers non-blocking

TDM and Signaling


Dial-pulse dialing from analog subscribers


Dial-pulse dialing to analog trunks


DTMF dialing from analog subscribers


DTMF dialing to analog trunks


Caller ID transmission towards analog subscribers


Caller ID detection on analog trunks

Automatic conversation recording for VoIP calls Yes (with licensing)

IP Telephony



10/100 BaseT

H.323 protocol, Version 5

SIP Session Initiation Protocol, RFC 3261 Yes
Telesis xSIP (eXtended SIP) protocol Yes
FTP (File Transfer Protocol) Yes
Adjunct protocol Yes
XDP (Xymphony Discovery Protocol) Yes
Dynamic DNS update client service Yes
G.711 audio codec Yes
G.723.1 (5.3 and 6.4kbps) audio codec Yes
G.729, G.729AB audio codec Yes

G.711 frame length

10 to 90msec

G.723.1 frame length

30 to 90msec

G.729, G.729AB frame length

10 to 90msec

Silence Suppression (VAD)


Echo Canceler G.168-2002 

QoS (Tos and Diffserv) Yes
T.30 Fax Pass-through for SIP Yes

Programmable ports / sockets

MD5 authentication Yes
H.235 Baseline Security Profile Yes
H.235 Baseline Security Profile with integrity Yes
Digest authentication Yes

Audio (voice) encryption

AES-256 (with licensing)

IP to TDM gateway capability


TDM to IP gateway capability


H.450 supplementary services

SIP supplementary services Yes
API (Application Program Interface) Yes
Automatic conversation recording for VoIP calls Yes (with licensing)
Hosting Java SIP client applet Yes

Related Readings

We recommend you to visit Telesis Wiki Pages for technical readings.


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