Telesis systems are designed, at least, according to the following international standards wherever applicable.
| Standard Code | Standard Name or Where the Telesis system uses it |
| ITU-T E.410 | International network management |
| ITU-T E.411 | International network management |
| ITU-T E.412 | Network management controls |
| ITU-T E.500 | Traffic intensity measurement principles |
| ITU-T E.502 | Traffic measurement requirements for digital telecommunication exchanges |
| ITU-T Q.23 | Technical features of push-button telephone sets |
| ITU-T Q.24 | Multifrequency push-button signal reception |
| ITU-T Q.35 | Technical characteristics of tones for the telephone service |
| ITU-T Q.541 | Digital exchange design objectives |
| ITU-T Q.542 | Digital exchange design objectives |
| ITU-T Q.543 | Digital exchange performance design objectives |
| ITU-T G.703 | Physical/electrical characteristics of hierarchical digital interfaces |
| ITU-T G.704 | Synchronous frame structures used at 1544, 6312, 2048, 8448 and 44 736 kbit/s hierarchical levels |
| ITU-T G.711 | Pulse Code Modulation (PCM) of voice frequencies |
| ITU-T G.712 | Transmission performance characteristics of pulse code modulation channels |
| ITU-T G.723 | Speech codec for VoIP |
| ITU-T G.726 | 40, 32, 24, 16 kbit/s adaptive differential pulse code modulation (ADPCM) |
| ITU-T G.729 | Speech codec for VoIP |
| ITU-T G.168 | Echo Canellation for VoIP |
| ITU-T Q.544 | Digital exchange measurements |
| ITU-T Q.781 | Signalling System No. 7 - MTP level 2 test specification |
| ITU-T Q.782 | Signalling System No. 7 - MTP level 2 test specification |
| ITU-T Q.784 | ISUP basic call test specification |
| ITU-T G.812 | Timing requirements of slave clocks suitable for use as node clocks in synchronization networks |
| ITU-T G.822 | Controlled slip rate objectives on an international digital connection |
| ITU-T G.823 | The control of jitter and wander within digital networks which are based on the 2048 kbit/s hierarchy |
| ITU-T G.920 | Digital sections at hierarchical bit rates based on a bit rate 2048 kbps |
| ITU-T G.930 | Digital line sections |
| ITU-T G.931 | Digital line sections |
| ITU-T K.20, K.21 | Resistibility of telecommunication equipment installed in a telecommunications centre to overvoltages and overcurrents |
| ETS-300 011 | Integrated Services Digital Network (ISDN) |
| ETS-300 051 | Integrated Services Digital Network (ISDN) |
| ETS-300 057 | Integrated Services Digital Network (ISDN) |
| ETS-300 089 | Integrated Services Digital Network (ISDN) |
| ETS-300 094 | Integrated Services Digital Network (ISDN) |
| ETS-300 102 | Integrated Services Digital Network (ISDN) |
| ETS-300 125 | Integrated Services Digital Network (ISDN) |
| ETS-300 129 | Integrated Services Digital Network (ISDN) |
| ETS-300 178 | Integrated Services Digital Network (ISDN) |
| ETS-300 186 | Integrated Services Digital Network (ISDN) |
| ETS-300 199 | Integrated Services Digital Network (ISDN) |
| ETS-300 206 | Integrated Services Digital Network (ISDN) |
| ETS-300 207 | Integrated Services Digital Network (ISDN) |
| ETS 300 239 | CTR4 (TBR4) |
| ETS-300 284 | Integrated Services Digital Network (ISDN) |
| ETS-300 347 | V5.2 AN and LE Protocol |
| ETS-300 356 | Integrated Services Digital Network (ISDN), SS7 ISUP |
| ETS-300 367 | Integrated Services Digital Network (ISDN) |
| ETS-300 402 | Integrated Services Digital Network (ISDN) |
| ETS-300 403 | Integrated Services Digital Network (ISDN) |
| ETS-300 659 | Voiceband Data Transmission Interface (Caller ID) |
| ECMA-143 | PISN ISDN (QSIG) |
| EN60950 | Low Voltage Directives |
| EN55022 | EMC ClassB |
| EN61000 3-2 | Harmonics |
| EN61000 3-3 | Flicker |
| EN61000 4-2 | ESD |
| EN61000 4-3 | Radiated |
| EN61000 4-4 | Burst AC Supply and Signal Lines |
| EN61000 4-5 | Surge AC Supply and Signal Lines |
| EN61000 4-6 | Conducted Immunity |
| EN61000 4-11 | Voltage Dips |
| AES FIPS PUB 197 | Media Encryption |
| RFC 3261 SIP | IP Telephony |
