AS551 VoIP

6 up to 30 channels GSM SIP-trunk

AS551 Master VoIP GSM gateway

The AS551 VoIP is an IP-based, modularly expandable GSM interface (GSM gateway) between PBXs and the mobile phone network. As a stand-alone hardware, it can be easily integrated into an existing IP network in order to integrate network-internal tariffs or low-cost time quotas into a call routing (LCR). Communication between the telephone system and the mobile radio networks can be carried out independently of the VoIP or fixed network service provider. This increases the independency of the communication channels of a company, an authority or other institution in case of line failure and partial line disruptions.

Detailed call numbers, routing tables, a separate callback management, etc., enable a customer-specific call organization and facilitate cost control. In the maximum setup, using an AS551 master with three AS551 slave units up to 30 GSM / UMTS / LTE radio channels in parallel are possible.

Further features for the AS551 VoIP are provided by so-called ‘extended features’ such as the TELNET control, the SNMP module, a Short-Message-API, the GSM Mobility Extender for the integration of mobile subscribers into a telephone system, etc.

All optional software extensions can be used with a free 28-day Test License.

Manual - EN
FAQ AS55x - DE

Functional Overview

Interfaces- 2,4,or 6 Quad-band radio modules for
  GSM 850/900, GSM 1800/1900
- Integrated antenna splitting
- LAN network 10/100 Base-T
- USB service interface
- Connetions for up to three
  AS551 Slave units with each
  8 additional radio channels
- Direct call can be defined individually
  for each radio channel
- Assignment of the radio channels by groups
- Call back unrestricted, limited by Blacklist,
  Whitelist or DTMF code
- Storing answered and unanswered calls
- The link extension call number is called
  mobile subscriber is stored in the device
  and is used for the call back.
- Callback request via SMS short message
- Very fast connection setup PBX
  to mobile radio
- Full dial-up capability
- GSM to IP number display (CLIP)
- Relocation from mobile to fixed
  with GME * (optional)
- SMS short messages via TELNET *
  or short news API *
  * With a software module (optional)
Overlap dialing- Limited dial-in by CLIP
> GSM to IP
Announcements- Operator guidance by various
  dial tones, melodies or voice announcements
  Individual announcements could be
  generated on demand.
- Causes (SIP response) are adjustable
- Built-in LCR functions, routing tables
  for destination and source call numbers
- Possibility of blocking certain numbers
  or prefixes
- Adjustable phone number display
- GSM minimum signal quality
  for connection setup
- Direct call per external GSM subscriber
  adjustable GSM> IP etc.
Maintenance- PC configuration software for Microsoft
  Windows© 9x/NT/2000/XP/VISTA/Windows 7,8,10
- Remote configuration and maintenance via LAN
  ReverseIP or GSM data channel
- Configuration and maintenance during operation
- Firmware update via LAN or via ReverseIP connection
- Operating status display via LEDs
- Troubleshooting by local or remote recording of
  logfiles (traces) which can be stored in text or
  Wireshark© format.
- Monitoring via SNMP*
* With a software module (optional)

Technical Data

Radio moduleCinterion MC55i or TC63i
GSM quad-band
Class 4 (2W at 850/900MHz)
Class 1 (1W at 1800/1900MHz)

(optional 3G)
Cinterion/Gemalto EU-3 UMTS or PH8
USB 2.0 Typ B (USB 1.1 kompatibel)
*Driver needs to be installed,
vie LAN-network, GSM CD-Data, ReverseIP
IP-interfaceRJ 45 Ethernet 10/100 Base-T
ProtocollsSIP 2.0 / UDP as a server,
Client or Peer-To-Peer
Additional protocolls:
Authentification: MD5
CodecG.711 µ-law, G.711 a-law
Interfaces AS55XMaster resp. Slave connector, RJ45
Short message
or API (optional)
AS551 Master:

AS551 Slave:
IP (SIP) - GSM interface
with 6 channels 19" rack (1U/84HP)
Extentions for AS551 Master
with 8 additional GSM channels
19" rack (1U/84HP)
IEC power connector,
integrated power supply
90 - 264 V AC
max. 1,8 A
47 - 440 Hz
Antenna1 Antenna splitter
6 x 1 (Master) for one SMA female
1 Antenna splitter
8 x 1 (Slave) for one SMA female.
Sizeapprox. W 485mm x H 45mm x D 300 mm,
equates to a 19'' rack 1U/84HP (DIN 41494 SC48D)
Weightapprox. 2500 Gramm
Power consumptionAS551 Master:
Stand by typically 90mA
Max. 150mA
equates 21 Watt resp. 35 Watt
(6 radio channels)
Gesprächsbetrieb typisch 150mA
Maximal 225mA
equates 35 Watt resp. 53 Watt
(6 radio channels)

AS551 Slave:
Stand by typically 120mA
Max. 200mA
equates 28 Watt resp. 47 Watt
(8 radio channels)
Gesprächsbetrieb typisch 200mA
Max. 300mA
equates 47 Watt respw. 71 Watt
(8 radio channels)
Work environmentOperating temperature:
5°C to 40°C
Storage temperature:
-10°C to 70°C
0% to 90%
Subject to modifications!