SIP Signaling - Virtual Address
- Kelli Higdon
SIP Load Balancing or SIP Direct Server Response utilizes a SIP Load Balancer and multiple SIP Servers to distribute SIP traffic. The IMG 2020 can be configured to act as a SIP Server within the SIP Load Balancing network. In a SIP Load Balancing network there would be one or more IMG 2020's configured as a SIP Server with one Load Balancer acting as a proxy to distribute the SIP traffic. To configure the IMG 2020 to function as a SIP Server, the SIP Virtual IP Address object must be configured. The SIP Virtual IP Address object will allow a user to configure a SIP Virtual IP address which is different than the IP address configured for normal SIP traffic. Each SIP Server must be configured with the same Virtual IP address and must be configured to NOT accept or Transmit Gratuitous ARPs. See below for more information on configuration etc.
Web GUI Page
Dialogic > IMG 2020 > Signaling > SIP Signaling > New SIP Virtual Address
Maximum Objects
Two SIP Virtual IP Address objects can be created per SIP Signaling object. This allows Load Balancer choice of two virtual IP's to send SIP traffic which will load balance SIP traffic on one IMG 2020.
Related Topics and Dependencies
To configure the IMG 2020 to act as a SIP Server there are other objects within the Web GUI that must get configured. Below is list of those dependencies along with links to any related topics.
The IP addresses that will be utilized by the SIP Virtual IP Address object are configured under the IP address object. First configure the IP Address object with the Physical interface set to CPU. Enter IP address being used in the SIP Load Balancing Network.
Within the IP Address object created set the Gratuitous ARP and ARP Responses field to Disable. By selecting Disable, this interface will not be able to issue a Gratuitous ARP. In addition whenever an external node attempts to ARP this Virtual IP Address, the ARP will be suppressed. Only nodes that know the VIP's MAC address will be able to send IP packets to it.
The SIP Virtual IP Address object can not be accessed until after the CPU interface has been created and the Gratuitous ARP and ARP responses field has been set to Disable.
IMG 1010 - SIP-Based Load Balancing - Virtual IP Address
IMG 1010 - SIP Signaling Object
Field Descriptions
IP Address
This drop-down will be populated with any Network Interface configured as a Service IP that have Gratuitous ARP and ARP Responses set to Disable. Select the desired entry. When the Gratuitous ARP and ARP Responses is set to Disable, the Virtual IP Address will not be allowed to issue a Gratuitous ARP. In addition, whenever an external node attempts to send an ARP to this Virtual IP Address, the ARP reply will be suppressed. Any node that knows the MAC address associated with this IP Address (through static configuration as used in Load Balancers) will be able to send packets to it. The Virtual IP Address will be able to send packets to any desired node since ARP Requests from the Virtual IP Address for an unknown IP’s MAC address will be allowed.
All outbound SIP requests will utilize the IP Address configured on the IMG 2020 for normal SIP Signaling even if the outbound transaction is within a dialog which had previously used the Virtual IP Address.
Port
Default = 5060. Can be modified by clicking in the Port field and enter new port number.