User's Manual

Table Of Contents
TD 92579EN
15 October 2014 / Ver. M
Installation and Operation Manual
IP-DECT Base Station & IP-DECT Gateway (software version 7.2.X)
149
Note: The Alt. Proxy 2 text field cannot be used if the Proxy and the Alt. Proxy 1 text
fields contain domain names.
In the Al
t. Proxy 3 text field: Enter the IP address or host name and optionally port
of proxy (e.g. proxy4.ascom-rd.com:5060) to the alternative SIP proxy (registrar).
Note: The Al
t. Proxy 3 text field cannot be used if the Proxy and the Alt. Proxy 1 text
fields contain domain names.
5 Reset in order to make the changes take effect, see 4.27 Reset.
D.2 Load Balancing Using Dynamic Connection Towards IP-PBX Network
When the number of users exceeds what an IP-PBX is able to register, you can use load
balancing towards an IP-PBX network. Using DNS services, users on each Master are
dynamically connected towards the IP-PBX network. In addition to the load balancing of
the traffic, redundancy is also achivied.
Figure 18. Load balancing using dynamic connection towards IP-PBX network.
D.2.1 How the Load Balancing Works
When you register a handset, a SRV-type query is sent to the DNS server asking for existing
SIP proxys (IP-PBXs) in the domain defined in the Master. The DNS server will reply with a
list of SRV (Service) records, one for each IP-PBX. Each SRV record contains a priority and a
weight value. Lower priority value means more preferred. When there are two or more
records with the same priority, then the weight value determines which IP-PBX the user
should be dynamically connected to.
A DNS server assign each user a primary and a secondary proxy address using DNS-SRV
service mechanism.
Master 0
Pari Master
Master 1
Master 2
IP-PBX
IP-PBX
IP-PBX
IP-PBX
DNS Server