Interfaces 4 FXS ports 1 WAN 10/100 Base-T 1 USB port VoIP protocols SIP
Voice codecs G.711 (a-law, µ-law) G.723.1 G. 726 (24 Kbps and 32 Kbps) G.729 (A/B) Fax transmission T.38 UDP Real-Time Fax G.711 (a-law, µ-law) pass-through Voice standards VAD (Voice Activity Detector) CNG (Comfort Noise Generation) AEC (Acoustic Echo Cancellation, G.168 recommendation) Functional features Payphones connection Subscriber line’s physical parameters measurement Local switching in case of a SIP-server connection failure VAS management via a phone Distinctive Ring Keep-alive during operation behind NAT Calling Party Control (CPC) DTMF Signal detection and generation Transmission by INBAND, RFC 2833, SIP INFO methods Supplementary services Call Hold Call Transfer Call Waiting Call forwarding when busy (CFB) Call forwarding on no reply (CFNR) Call forwarding unconditional (CFU) Calling line identification (FSK Type I, FSK Type II, DTMF) Calling Line Identification Restriction (CLIR) Hotline/Warmline Call Group 3-Way Conference Pickup Group Hunt groups A dedicated server for 3-Way Conferencing (RFC 4579) VoIP functions Local connection switching Operation without a SIP server Flexible dial plan Management profiles for FXS ports SIP profiles (support for up to 8 profiles) Geographical redundancy of a SIP server (up to 4 redundant SIP servers) Application of settings without reboot Voice transmission through a protected channel (encryption through Ipsec) IMS (3GPP TS 24.623) for Call Hold, Call Waiting, 3-Way Conference, Hotline management Using SIP servers from DHCP-option 120 Support for operation behind NAT (STUN and Public IP) Setting custom call-control signals Quality of service (QoS) DSCP and 802.1p assignment for SIP and RTP packets Bandwidth redundancy Network functions Different protocols for connection to a service provider network (Static, DHCP, PPPoE, PPTP, L2TP) Local DNS server Static and dynamic routing VLAN per service (VLAN for each service: Internet, VoIP, Management) Firewall Operation via 3G/4G USB modems with connection redundancy Print server IPsec (for voice transmission and remote control) Management Web interface (multilingual* ) SNMP (phone parameters configuration, monitoring and statistics gathering) Telnet Syslog Tcpdump SSH TR-069 (Eltex.ACS server is recommended) DHCP-based autoprovisioning (43, 66, 67 DHCP options) Management via IPsec encrypted channel Security Username and password authentication Firewall Access rights differentiation for admin/user Password encryption Digest authorization USB port USB storage connection with FAT/FAT32/EXT2/EXT3/NTFS file systems — file exchange according to FTP protocol USB 3G/4G modems connection — 3G/4G channels redundancy Printer connection — setting up a print server Technical features SDRAM 256 MB Flash 32 MB OS Linux Specifications RFC 3261 SIP 2.0 RFC 3262 SIP PRACK RFC 4566 Session Description Protocol (SDP) RFC 3263 Locating SIP servers for DNS lookup SRV and A records RFC 3264 SDP Offer/Answer Model RFC 3311 SIP Update RFC 3515 SIP REFER RFC 3891 SIP Replaces Header RFC 3892 SIP Referred-By Mechanism RFC 4028 SIP Session Timer RFC 2976 SIP INFO Method RFC 2833 RTP Payload for DTMF Digits, Flash event RFC 3108 Attributes ecan and silenceSupp in SDP RFC 4579 SIP Call Control - Conferencing for User Agents RFC 3361 DHCP Option 120 RFC 3550 RTP A Transport Protocol for Real-Time Applications * Supported in the firmware version 1.2.1 and higher