SIP Server configuration options

SIP Server Application > TServer section

geo-location

Default Value: No default value
Valid Value: Any alphanumeric string
Changes Take Effect: Next Call

Specifies a string identifying the data center to which the application belongs. All applications in the same data center must have the same value of this parameter specified.

sip-address

Default Value: NULL
Valid Values: Any valid IP address or host name
Changes Take Effect: After SIP Server restart

Specifies an IP address of the SIP Server interface. This option must be set when deploying SIP Server on a host with multiple network interfaces. SIP Server uses this value to build the Via and the Contact headers in SIP messages. When this option is not set, SIP Server attempts to detect the IP address automatically.

This option is mandatory for the SIP Server running in cluster mode. SIP Proxy applications read this parameter to identify how to communicate with SIP Server nodes in the cluster through SIP.

sip-port

Default Value: 5060
Valid Value: Any valid TCP/IP port
Changes Take Effect: After SIP Server restart

Specifies the port on which SIP Server listens for incoming SIP requests. The same port number is used for both TCP and UDP transports.

sip-enable-rfc3263

Default Value: false
Valid Value: true, false
Changes Take Effect: After SIP Server restart

Specifies how SIP Server uses the information obtained through DNS SRV resolution. To support this functionality, you must enable both the internal DNS client (option sip-enable-gdns) and Active Out-of-Service for the destination.

When multiple transports (protocol, IP address, port) are available for the destination, this option determines which transport SIP Server will select.

To use priority and weight, set this option to true. To treat all destinations as equal, set this option to false.

If you set this option to true, SIP Server includes priority and weight information obtained through DNS SRV resolution to the destination selection procedure. This is in accordance with RFC 3263 and RFC 2782. SIP Server ignores the contacts-backup option as redundant.

If you set this option to false, SIP Server ignores priority or weight information when applying the destination selection procedure (multiple active destinations are given equal ranking). Additional transports can be configured using the contacts-backup option.

sip-enable-gdns

Default Value: true
Valid Values: true, false
Changes Take Effect: After SIP Server restart

Specifies the DNS name resolution mode.

If this option is set to true, SIP Server uses its internal DNS client to perform DNS lookups by querying the local DNS server available on the network. When resolving a contact that has Active Out-of-Service detection enabled but does not have a port specified, SIP Server performs DNS SRV resolution. If SRV resolution fails, SIP Server tries A/AAAA record resolution using default ports.

If this option is set to false, SIP Server resolves the DNS names using the local operating system DNS client. In this case, SIP Server is unable to perform DNS resolution for SRV records. When resolving a contact that does not have a port specified, A/AAAA record resolution is executed using default ports.

The default port for UDP/TCP is 5060, while the default for TLS is 5061.

SIP Server does not support NAPTR record lookup.

sip-outbound-proxy

Default Value: false
Valid Values: true, false
Changes Take Effect: After SIP Server restart

Set this option to true when SIP Server is deployed in a SIP Cluster environment and all SIP messages are sent through the SIP Proxies. When this option is set to true, SIP Server looks for a VoIP Service DN with service-type=sip-outbound-proxy. For each initial out-of-dialog outgoing SIP request, SIP Server inserts a Route header with the value of DN contact. When multiple SIP Proxies are represented as FQDN, SIP Server resolves FQDN through DNS to a list of SIP Proxy IP addresses. Selection of a specific outbound SIP Proxy is “sticky” for a SIP dialog. That is, once a specific outbound proxy instance (IP address, port & transport protocol) is selected for a SIP dialog and in the route path, that instance is used for all transactions within the dialog, unless the proxy instance fails. This is a deviation from RFC 3263 section 4, with the purpose of enhanced scalability and performance. If that instance fails, then the next transaction would require selection of a new outbound SIP proxy instance which would again be a “sticky” selection. SIP Proxy for a new SIP dialog is selected in round-robin fashion.

http-port

Default Value: 0
Valid Values: Any valid TCP/IP port
Changes Take Effect: After SIP Server restart

If the option is specified, SIP Server functions as a WEB Server and listens for incoming HTML requests. SIP Server reports to http clients its operational information, such as the number of calls, dialogs, CPU usage, and so on. Information is reported as an HTML document. This functionality is intended to be used by Feature Server/SIP Voicemail to represent real-time and historical operational statistics of SIP Cluster and is not intended to be used by other means.

SIP Server Application > extrouter section

cluster-role

Default Value: off
Valid Values: off, iscc-node, iscc-proxy
Changes Take Effect: Immediately

Specifies the role that this SIP Server plays in the multi-site scenarios in the SIP cluster. The default value off is valid only for a SIP Server running in a non-cluster mode. Set to the value of iscc-proxy for each SIP Server instance that acts as a proxy in a SIP cluster environment. Set to the value of iscc-node for each SIP Server instance that does not act as a proxy in a SIP cluster environment.

Note: Setting this option to a value of iscc-proxy or iscc-node is mandatory for all SIP Server instances in the cluster. Failure to do so may affect the multi-site SIP Server routing and the Agent Reservation feature.

pct-ci-req-tout

Default Value: 500 msec
Valid Values: Timeout value format
Changes Take Effect: For the next request

Specifies the time interval during which SIP Server waits for call data requested with respect to a call originated at another site. All events related to this call will be suspended until either the requested call data is received or the specified timeout expires. This option applies only to SIP Server in cluster mode.

pct-rci-tout

Default Value: 10 sec
Valid Values: Timeout value format
Changes Take Effect: For the next operation

Specifies the time interval that SIP Server waits for call data from other SIP Server transactions. Counting starts when pct-ci-req-tout expires.

proxy-name

Default Value: Empty string
Valid Values: The primary SIP Server application name with the cluster-role option set to iscc-proxy.
Changes Take Effect: After SIP Server restart

Specifies the name of the SIP Server acting as a proxy in the cluster environment (cluster-role=iscc-proxy) that is used for association of External Routing Point resources. If the option has a valid value, this SIP Server manages allocation of External Routing Point resources with the matching DN-level proxy-name configuration option.

Notes:

• For the SIP Server acting as a proxy, this option must have a non-empty string as a value. It is recommended to set this option value to the same application name of the primary SIP Server in the SIP Server HA pair.
• If SIP Server has the cluster-role option set to a value of iscc-proxy and the proxy-name option has a default value (an empty string), SIP Server prints an error message to the SIP Server log and immediately triggers application shutdown.

DN-level options for service-type=sip-cluster-nodes

active-applications

Default Value: Empty string
Valid Values: Comma-separated list of the names of active SIP Server applications
Changes Take Effect: Immediately

Only applications that are currently running must be listed in this parameter. Only primary instances of the SIP Server HA pairs must be included into this list.

applications

Default Value: Empty string
Valid Values: Comma-separated list of primary SIP Server Applications presented in the cluster
Changed Take Effect: After SIP Server restart

In the comma-separated list, include all SIP Server instances for all data centers regardless of their current status (running or shut down). Only primary instances of the SIP Server HA pairs must be included into this list.

sipproxy-applications

Default Value: Empty string
Valid Values: Comma-separated list of names for all active SIP Proxy Applications in the cluster
Changes Take Effect: Immediately

Specifies the list of SIP Proxy applications. Include all SIP Proxy instances that serve different data centers.

DN-level options for service-type=sip-outbound-proxy

In the cluster, both incoming and outgoing traffic for all cluster nodes is passed through the SIP Proxy instances. Only one DN of this type must be configured in the SIP Server cluster switch. Multiple SIP Proxies are represented by a single FQDN name, which is configured on the DNS Server to be resolved to SRV list. Each record in this list points to one instance of SIP Proxy. To support this functionality, DNS SRV record support should be enabled in the SIP Server as follows:

• Set both sip-enable-gdns and sip-enable-rfc3263 to true in the SIP Server application.
• Enable Active Out-of-Service detection for the SIP Outbound Proxy DN.

It is required to configure equal weights and priorities for all records in the SRV list on the DNS server.

SIP Server tries to equally distribute the initial outgoing SIP request among available SIP Proxies, in round robin fashion. Selection of a specific outbound SIP Proxy is “sticky” for a SIP dialog. That is, once a specific outbound proxy instance (IP address, port, protocol) is selected for a SIP dialog and added in the route path, that instance is used for all transactions within the dialog, unless the proxy instance fails. This is a deviation from RFC 3263 section 4, with the purpose of enhanced scalability and performance. If that instance fails, then the next transaction would require selection of a new outbound SIP proxy instance which would again be a “sticky” selection.

contact

Default Value: No default value
Valid Values:FQDN of SIP Proxy resolved to SRV list
Changes Take Effect: Immediately

Set this option to the Fully Qualified Domain Name (FQDN), which resolves to the SRV list of the SIP Proxy addresses. SIP Server uses this list to load balance the traffic across all SIP Proxy instances. To localize SIP traffic inside one data center, this FQDN must be resolved to different sets of SIP Proxies based on geo-location: in other words, SIP Server should be aware only about those SIP Proxy instances installed in the same data center where SIP Server resides.

external-contact

Default Value: No default value
Valid Values: FQDN of SIP Proxy resolved to A-record (host:port)
Changes Take Effect: Immediately

Set this option to the FQDN used by the SIP phones to access the SIP Proxy instances in the cluster. Use the following format:
host:port Where host is an FQDN that can be resolved using DNS to a list of SIP Proxy IP Addresses (DNS A records), port is the TCP/IP port that SIP Proxy uses to listen for sip messages from SIP phones (all SIP Proxy instances listen on the same port). For example:
anyproxy.DnsServer.com:7018

Additional Configuration

In addition to these options, you must also configure the following:

• oos-check — Set this option to 3
• oos-force — Set this option to 5
  These two options (oos-check and oos-force) enable Active Out-of-Service Detection. In this specific example, SIP Server is checking for proxies (by using value of the contact option) every 3 second and sets them in out-of-service state after 5 seconds after the last check that was not responded.
• service-type — Set this option to sip-outbound-proxy.

SIP Cluster switch >DN of type External Routing Point > TServer

proxy-name

Default Value: Empty string
Valid Values: The primary SIP Server application name acting as a proxy in the cluster
Changes Take Effect: Immediately

Mandatory option. Specifies the name of the primary SIP Server application name acting as a proxy which manages allocation of this External Routing Point (ERP). The option must not be empty, otherwise, the ERP resource will not be available for inbound multi-site transactions.