| Telephone Interfaces | GXW4216/24/32 x RJ11 FXS ports plus & 1/1/2 x 50 pin Telco connectors GXW4248: 2 50 pin Telco connectors |
| Network Interfaces | 1 x 10M/100M/1000Mbps auto-sensing RJ45 port |
| Audio Codecs | G.711, G. 723, G.726 (40/32/24/16), G.729A/B/E, iLBC |
| LED Indicators | LAN Link, LAN Activity, Per Telephone port |
| LCD Display | Backlit 128x32 grpahic LCD display with support for multiple languages |
| Voice-over-Pack Capabilities | G.168 carrier grade line echo cancellation, dynamic jitter buffer, modem detection & auto-switch to G.711 |
| Voice Compression | G.711, G.723, G.726, G.729 A/B, iLBC |
| Fax over IP | T.38 compliant Group 3 Fax Relay up to 14.4kbps and auto-switch to G.711 for Fax Pass-through, Fax Datapump V.17, V.21, V27ter, V29 for T.38 fax relay |
| Telephony Features | Caller ID display or block, call waiting, blind or attended transfer, call forward, do not disturb, 3-way conference, last call return, paging, message waiting indicator LED (NEON LED) support and stutter tone, auto dial, flexible dial plan |
| QoS | DiffServ, TOS, 802.1P/Q VLAN tagging |
| Network Protocols | TCP/UDP, RTP/RTCP, HTTP/HTTPS, ARP, ICMP, DNS, DHCP, NTP, TFTP, PPPoE, STUN, LLDP |
| DTMF Method | Flexible DTMF transmission methods including In-audio, RFC2833, and /or SIP INFO |
| Singaling | SIP (RFC 3261) over UDP/TCP/TLS |
| SIP Server Profiles & Accounts Per System | 4 distinct SIP server profiles per system and independent SIP account per telephone port |
| Provisioning | TFTP, HTTP, HTTPS, TR069 |