Kuhnt AS55 Series Service Manual Download

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SERVICE MANUAL AS55X

55Xseries_manual_V3.22 (18-08-15)

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1.5

GSM channel groups

The  routing  function  of  the  AS55x  does  not  work  via  single  GSM  channels,  because  of  the
higher channel number. Single channels can be combined to a group, but a group might also
consist of only one channel. Therefore, if the user does not want to work with groups, he can
simply  assign  one  channel  to  each  group  (the  configuration  for  GSM  groups  can  do  such
assignment  automatically).  Normally  a  GSM  channel  group  consists  of  channels,  registered
to the same GSM network. Routing functions of the AS55x point to groups. The selection of a
channel  within  a  group  is  alternating,  i.e.  all  channels  of  a  group  statistically  will  have  the
same load.

One GSM channel can be a member of different groups, e.g. one group points to a VPN and
another one points to a GSM network.

For programming instructions see 5.9.3.

1.6

VPN

Virtual  private  networks  (VPN)  in  GSM  can  significantly  decrease  costs,  especially  if  GSM
channels  of  an  AS55x  are  members  of  VPNs.  Further  characteristics  of  VPNs  are  that
members of a VPN can call each other via short user numbers without network prefixes, the
CLIP from member to member is displayed as such short user number as well.

The AS55x provides a special support for a comfortable access to GSM channels, which are
members of VPNs.  In  order to  separate  VPN user  numbers  from  subscriber number  at the
PBX, a VPN prefix has to be created for each GSM channel of the AS55X that is  part of the
VPN.  From  the  sight  of  the  PBX,  this  GSM-VPN  is  an  independent  network  with  its  own
prefix.  For  a  dialling  to  a  user  of  this  network,  the  VPN  prefix  has  to  lead  the  VPN  user
number. All routing functions of the AS55x can be used via this VPN prefix. For a call-setup
from a VPN member to the PBX, the AS55x adds the VPN prefix, so the PBX subscriber can
identify  the  caller  as  a  VPN  member.  Callbacks  will  be  routed  correctly  because  of  the
consequent use of the VPN prefix.

Example: The GSM channel 3 of an AS55x is a member of a VPN with the user number 4444.
The created VPN prefix for this GSM channel is +49123 (the VPN prefix has to be defined in
international order, here with the German country code). A PBX subscriber wants to call the
VPN member 5555, so he can dial 01235555 if the location of the PBX is in Germany as well.
The  appropriately  configured  AS55x  will  route  this  call  via  GSM  channel  3.  If  this  VPN
member is calling a PBX subscriber himself, his number will also be displayed as 01235555.

If  there  is  much  traffic  with  a  GSM  VPN,  multiple  channels  of  an  AS55x  may  get  the  same
VPN prefix. These channels are combined to a GSM channel group and the routing function
of the AS55x chooses one ready channel of this group if a call-setup to this VPN is made.

For programming instructions see 5.8.3, 5.10.2, 5.10.3, 5.11.1 and 5.11.5