Configuring SIPREC

This section defines the information required to configure SIPREC on the Oracle® Enterprise Session Border Controller. It also provides a sample procedure for configuring SIPREC using the Acme Packet Command Line Interface (ACLI).

Session Recording Server (SRS)

The Oracle Communications Interactive Session Recorder’s RSS acts as the SRS in the network. A session-recording-server attribute under the session-router object in the Oracle® Enterprise Session Border Controller ACLI allows you to enable/disable the SRS. This object is the session recording server that receives replicated media and records signaling. Additional parameters for SRS are configured under the session-agent, realm-config, and sip-interface objects. The rules of precedence for which the Oracle® Enterprise Session Border Controller uses these parameters are: 
session-agent takes precedence over the realm-config, and realm-config takes precedence over sip-interface.

Each SRS is associated with a realm-config. The realm specifies the source interface from which replicated traffic originates. The destination is an IP Port parameter (IP address or hostname with an optional port) that defines the SIP address (request URI) of the actual SRS.

For an additional level of security, Oracle recommends the SRS be configured in its own realm so as to apply a set of access control lists (ACLs) and security for the replicated communication.

Although the Oracle® Enterprise Session Border Controller supports large UDP packets, Oracle recommends the sip-interface associated with the SRS realm, be provisioned with a TCP port.

Enforcing Parity Check on Media Port Numbers with the SRS

You can configure the ESBC to enforce media port number parity on flows between the ESBC and the SRS, as discussed in RFC 4566. By default, the ESBC does not consider port number parity when assigning or recognizing RTP and RTCP flows in SDP session descriptions. This can result in signaling issues, including one-way audio recording, when the recording server and the ESBC establish flows that have a port number conflict.

By default, the ESBC does not enforce port number parity for RTP and RTCP flows to the SRS, acting as the UAS callee on the east side interface. This parity defines the use of an even port for RTP and the subsequent odd port for RTCP. The force-parity parameter causes the ESBC to behave as follows when receiving port number is the SDP m-line from the SRS:

  • Disabled - The ESBC accepts both odd and even ports on the m-line. The ESBC sends both rtp and rtcp to this same port.
  • Enabled - The ESBC rejects odd ports on the m-line, and accepts even ports. Upon receiving an even port, the ESBC sends rtp to the even port and rtcp to (rtp+1), which is an odd numbered port.

You enable the force-parity parameter on the applicable session-recording-server.

ACMEPACKET(session-recording-server)# force-parity enabled

Session Recording Group

The Oracle® Enterprise Session Border Controller uses the session-recording-group attribute under the session-router object in the ACLI to set high availability (HA) for 3rd party call recorders. Using this object, you can define a collection of one or more SRSs. The Oracle® Enterprise Session Border Controller utilizes SIP’s transport mechanism and keeps track of statistics on each SRS to manage the distribution of traffic and load balancing. (For more information on Oracle® Enterprise Session Border Controller load balancing in session recording groups, see Load Balancing). When multiple SRSs are in a session recording group, the Oracle® Enterprise Session Border Controller uses heuristics to intelligently route the recording dialog to one or more SRSs utilizing the selection strategy.

The simultaneous-recording-servers configuration attribute controls the number of simultaneous SIP dialogs that the Oracle® Enterprise Session Border Controller establishes to the SRSs in the session recording group per communication session. For instance, if a session recording group contains 3 SRSs, and simultaneous-recording-servers is set to 2, the recording agent initiates a SIP INVITE to the next two SRSs based on the session recording group strategy. In this way, duplicative recording sessions are instantiated, allowing for recording redundancy in multiple SRSs or within a session recording group.

Note:

The Oracle® Enterprise Session Border Controller streams media to all SRSs. Each SRS chooses whether or not to ignore the media by returning a recvonly(receive only) media line. This permits an SRS to select specific media to record in the recording session, as well as determine whether or not to record the media.

The number of simultaneous recording servers does not dictate the number of recording devices required to be active for a communication session. If two SRSs exist in a session recording group and simultaneous-recording-servers is set to 2, if at least one recording device to any of the servers completes, the recording server is treated as being established.

Load Balancing

The Oracle® Enterprise Session Border Controller supports recording server load balancing across members of a session recording group using the following strategies:

Note:

SRS groups support “round-robin” and “hunt” strategies only.

[Round-robin]: The Oracle® Enterprise Session Border Controller remembers the last SRS that was used. Each new recording session selects the next SRS in the session recording group. When simultaneous-recording-servers is greater than 1, the next n recording servers are selected from the session recording group.

[hunt]: The Oracle® Enterprise Session Border Controller successively attempts to contact SRSs in the session recording group until a successful recording dialog is established with the SRS, starting from the first SRS in the session recording group. The Oracle® Enterprise Session Border Controller attempts to contact each SRS in the session reporting group once. When contact is exhausted, the recording device is considered failed. A SIP failure (response greater than 399, timeout or TCP setup failure) causes the Oracle® Enterprise Session Border Controller to attempt the next possible SRS. When simultaneous-recording-servers is greater than 1, the Oracle® Enterprise Session Border Controller attempts to establish n recording devices in a hunting fashion.

Session Recording Group within Logical Remote Entities

Each logical remote entity (session-agent, realm-config and sip-interface) has a session-recording-server attribute.This attribute is a reference to a specific SRS configuration and can be used to specify a session recording group instead. If a session recording group is specified instead of an SRS, the session recording group name must be prefixed with "SRG:" followed by the session recording group name. This distinguishes between an SRS being referenced and a session recording group being referenced.

With SIPREC, if an SRS or session recording group is configured on both the ingress and egress logical remote entities, both the ingress and egress SRS/session recording groups are used. This means that the Oracle® Enterprise Session Border Controller records the media between participants twice (or more) - once for the ingress recorders and once for the egress recorders.

If both the ingress and egress SRS/session recording group are the same, the Oracle® Enterprise Session Border Controller makes an optimization and only records the media once. Even if the ingress session recording group is the same exact set of SRSs as the egress session recording group (but with a different name), the Oracle® Enterprise Session Border Controller replicates media to both destinations. However, if the same set of SRSs has the exact same identifier, the 
Oracle® Enterprise Session Border Controller sends media to one and not both SRSs.

Selective Recording

SIPREC defines a number of use cases for which the Oracle® Enterprise Session Border Controller can record communication sessions. These use cases include the use of selective based recording. A selective recording is one in which a unique recording server is created per communication session.

Note:

The Oracle® Enterprise Session Border Controller does not support persistent recording.

For SRSs using selective recording, recording servers are unique per session recording group. For each selective SRS in a session recording group, during the setup of a new communication session, the recording metadata is the same for each recording device. The SRC initiates a new SIP INVITE to the SRS carrying the metadata for that new recording server. The recording agent terminates the SIP dialog at the time that the recording session ends.

The lifetime of a recording session extends beyond the lifetime of the recorded communication. The SRC (Oracle® Enterprise Session Border Controller) re-uses the recording session ID in the metadata instead of creating a new ID for each recording.

High Availability (HA) Support

An Oracle® Enterprise Session Border Controller using SIPREC supports HA in the network. The Oracle® Enterprise Session Border Controller replicates all metadata states between the active and standby Oracle® Enterprise Session Border Controllers. Any recording dialogs in progress do not survive the failover, but all calls in progress are preserved. Additionally, the recording dialogs are replicated as well to the failed over Oracle® Enterprise Session Border Controller so that in-dialog SIP requests continue to function.

Each recorded communication session replicated to a single SRS counts as two calls instead of one. The Oracle® Enterprise Session Border Controller creates two flows between the two participants and two additional flows to the SRS for each of the parent flows.

SIPREC Configuration Procedure

The following configuration example assumes the Oracle® Enterprise Session Border Controller has the session recording license enabled on the Oracle® Enterprise Session Border Controller. Changes to the call session recording configuration for SIPREC are dynamic. Active calls in progress remain unaffected by the configuration changes. New calls, however, utilize the changes after a Save and Activate of the configuration.

The following attributes must be configured:

  • session-recording-server
  • session-recording-group (for RSS or 3rd party SRS high availability (HA) only)

and at least one of the following attributes:
  • realm-config
  • session-agent
  • sip-interface

Session-recording-server Attribute

To configure the session-recording-server attribute:

  1. In Superuser mode, type configure terminal and press Enter.
    ACMEPACKET# configure terminal
  2. Type session-router and press Enter to access the session router-related objects.
    ACMEPACKET(configure)# session-router
    ACMEPACKET(session-router)#
  3. Type session-recording-server and press Enter to access the session recording server-related attributes.
    ACMEPACKET(session-router)# session-recording-server
    ACMEPACKET(session-recording-server)#
  4. name — Enter a unique name for the session recording server. This name can be referenced when configuring realm-config, session-agent, and sip-interface. Valid values are alpha-numeric characters. Default is no value specified.
    ACMEPACKET(session-recording-server)# name SRS1
  5. (optional) description — Enter a description for the session recording server. Valid values are alpha-numeric characters. Default is no value specified.
    ACMEPACKET(session-recording-server)# description <recording server name>
  6. realm — Enter the realm for which the session recording server belongs. Valid values are alpha-numeric characters. Default is no value specified.
    ACMEPACKET(session-recording-server)# realm <realm name>

    Note:

    Oracle recommends that the session recording server be configured in its own realm.
  7. mode — Enter the recording mode for the session recording server. Valid values are:
    • selective (default) - Unique recording server created per communication session

    • persistent - Not supported.

    ACMEPACKET(session-recording-server)# recording-mode selective
  8. destination — Enter the destination IP address with IP port (port specification is optional) that defines the SIP address (request URI) of the session recording server. Enter values in the format 0.0.0.0:<port number>. Default is no value specified.
    ACMEPACKET(session-recording-server)# destination 172.34.2.3:5060
  9. port — Enter the port number to contact the session recording server. Valid values are 1024 to 65535. Default is 5060.
  10. transport-method — Enter the protocol that the session recording server uses to accept incoming packets from the session reporting client on the network. Default is DynamicTCP. Valid values are:
    • “” - No transport method used. Same as leaving this parameter value blank.
    • UDP - User Datagram Protocol (UDP) is used for transport method.
    • UDP+TCP - UDP and Transmission Control Protocol (TCP) are used for transport method.
    • DynamicTCP - One TCP connection for EACH session is used for the transport method.
    • StaticTCP - Only one TCP connection for ALL sessions is used for the transport method. This option saves resource allocation (such as ports) during session initiation.
    • DynamicTLS - One Transport Layer Security (TLS) connection for EACH session is used for the transport method.
    • StaticTLS - Only one TLS connection for ALL sessions is used for the transport method. This option saves resource allocation (such as ports) during session initiation.
    • DTLS - Datagram TLS is used for the transport method.
    • TLS+DTLS - TLS and DTLS are used for the transport method.
    • StaticSCTP - Only one Stream Control Transmission Protocol (SCTP) connection for ALL sessions is used for the transport method. This option saves resource allocation (such as ports) during session initiation.
      ACMEPACKET(session-recording-server)# protocol UDP
  11. force-parity —Enable to enforce port number parity for flows between the system and the session recording server. Default is disabled.
    ACMEPACKET(session-recording-server)# force-parity enabled
  12. Enter done to save the session recording configuration.
    ACMEPACKET(session-recording-server)# done

Configure Session-Recording-Group

The Oracle® Enterprise Session Border Controller (ESBC) uses the session-recording-group attribute under session-router to define a collection of session recording servers.

  • Enable the SIP Session Recording licence. See "Getting Started."
  • Configure multiple session recording servers. See "Session-recording-server Attribute."
  • Determine the load balancing strategy that you want the ESBC to use. See "Load Balancing."

In the configuration, you list the session recording servers that you want in the group, select a load balancing strategy, and set the number of simultaneous SIP dialogs.

  1. Access the session-recording-group configuration element.
    ORACLEORACLE# configure terminal
    ORACLE(configure)# session-router
    ORACLE(session-router)# session-recording-group
    ORACLE(session-recording-group)#
  2. Do the following:
  3. Type done to save the configuration.

Session-recording-group Attribute (for HA only)

For environments that required high availability (HA) requirements, configure the session-recording-group attribute.

To configure the session-recording-group attribute and enable HA:

  1. In Superuser mode, type configure terminal and press Enter.
    ACMEPACKET# configure terminal
  2. Type session-router and press Enter to access the session router-related objects.
    ACMEPACKET(configure)# session-router
    ACMEPACKET(session-router)#
  3. Type session-recording-group and press Enter to access the session recording group-related attributes.
    ACMEPACKET(session-router)# session-recording-group
    ACMEPACKET(session-recording-group)#
  4. name — Enter a unique name for the session recording group that is a collection of one or more session recording servers. This name can be referenced when configuring realm-config, session-agent, and sip-interface. Valid values are alpha-numeric characters. Default is no value specified.
    ACMEPACKET(session-recording-group)# name <SRG Group Name>

    Note:

    The name of the session recording group must be prefixed with SRG.
  5. (optional) description — Enter a description for the session recording group. Valid values are alpha-numeric characters. Default is no value specified.
    ACMEPACKET(session-recording-group)# description <Recording Group Name>
  6. session-recording-servers — Enter the names of the session recording servers that belong to this session recording group. Valid values are alpha-numeric characters. Default is no value specified.
    ACMEPACKET(session-recording-group)# session-recording-servers SRS1,SRS2

    Note:

    You must enter multiple servers as values for the session-recording-servers attribute.
  7. strategy — Enter the load balancing strategy that the session reporting client (Oracle® Enterprise Session Border Controller) uses when sending recordings to the session reporting server. Valid values are:
    • Round-robin (default) - The Oracle® Enterprise Session Border Controller remembers the last SRS that was used. Each new recording session selects the next SRS in the session recording group. When simultaneous-recording-servers is greater than 1, the next n recording servers are selected from the session recording group.

    • hunt - The Oracle® Enterprise Session Border Controller successively attempts to contact SRSs in the session recording group until a successful recording dialog is established with the SRS, starting from the first SRS in the session recording group. The Oracle® Enterprise Session Border Controller attempts to contact each SRS in the session reporting group once. When contact is exhausted, the recording device is considered failed. A SIP failure (response greater than 399, timeout or TCP setup failure) causes the Oracle® Enterprise Session Border Controller to attempt the next possible SRS. When simultaneous-recording-servers is greater than 1, the Oracle® Enterprise Session Border Controller attempts to establish n recording devices in a hunting fashion.

    • least busy - For some 3rd party recording devices, the number of concurrent recording servers proves to be the most taxing for system resources. The Oracle® Enterprise Session Border Controller tracks the number of recording servers active to a given SRS at any given time. It uses this information to determine which SRS would be the best candidate for the next RS. The SRS with the fewest number of active recording servers receives the next RS. If two or more SRSs in a session recording group currently have the same number of active recording servers, the SRS configured first in the session recording group takes precedence.

    • lowest sustained rate (fewest-setups-per-minute) - For some 3rd party recording servers, processing large amounts of sessions in a short amount of time proves to be the most taxing on their system's resources. The Oracle® Enterprise Session Border Controller tracks the number of recording server setups over a sliding window of five minutes. The SRS within the session recording group with the fewest setups per the window of time is selected as the next candidate for receiving the recorded session. If two or more SRSs in a session recording group currently have the same value for setups in the given window of time, then the SRS configured first in the session recording group takes precedence.

      ACMEPACKET(session-recording-group)# strategy round-robin
  8. simultaneous-recording-servers — Enter the number of simultaneous SIP dialogs that the session reporting client (Oracle® Enterprise Session Border Controller) establishes to the session reporting servers in the session reporting group per communication session. Valid values are 1 to 3. Default is 0.
    ACMEPACKET(session-recording-group)# simultaneous-recording-servers 2
  9. Enter done to save the session recording group configuration.
    ACMEPACKET(session-recording-group)# done
  10. Enter exit to exit the session recording group configuration.
    ACMEPACKET(session-recording-group)# exit
  11. Enter exit to exit the session-router configuration.
    ACMEPACKET(session-router)# exit
  12. Enter exit to exit the configure mode.
    ACMEPACKET(configure)# exit
  13. Enter save-config to save the session recording group configuration.
    ACMEPACKET# save-config
  14. Enter activate-config to activate the session recording group configuration.
    ACMEPACKET# activate-config

Realm-config Attribute

Use the following procedure to configure the realm-config attribute and enable session recording:

  1. Access the realm-config configuration element.
    ORACLE# configure terminal
    ORACLE(configure)# media-manager
    ORACLE(media-manager)# realm-config
    ORACLE(realm-config)# 

  2. session-recording-server — Enter a space-separated list containing up to four names of session-recording-servers, or session-recording-groups, or a combination of both exisiting in the realm associated with the session reporting client (Oracle® Enterprise Session Border Controller). For each entry, use '+' to add, '-' to remove, and omit to replace the list. For example, realm-config# session-recording-server "srs1 srs2 srs4 SRG:srg1". Enter a ? to view a list of all acceptble name formats. Press the TAB key after the session-recording-server to view a list of configured SRSs and SRGs. For each entry, use + to add, - to remove, and omit to replace the list.
    Do not use the format +srs1 -srs1. In this case, srs1 is still retained even after using -srs1in the command.
    ACMEPACKET(realm-config)# session-recording-server <srs-name>
    or

ACMEPACKET(realm-config)# session-recording-server SRG:<group-name>

    Note:

    The value for this attribute is the name you specified in the session-recording-server attribute. If specifying a session-recording-group, you must precede the group name with "SRG:".
  3. session-recording-required — Enter whether you want a call to be accepted by the Oracle® Enterprise Session Border Controller when recording is not available. The default value is disabled.
    • Enabled — Restricts call sessions from being initiated when a recording server is not available.

    • Disabled (default) — Allows call sessions to initiate even when the recording server is not available.

      Note:

      Oracle recommends that the session-recording-required parameter remain disabled.
  4. session-max-life-limit — Enter the maximum interval in seconds before the SBC must terminate long duration calls. The value supercedes the value of session-max-life-limit in the sip-interface and sip-config configuration elements and is itself superceded by the value of session-max-life-limit in the session-agent configuration element. The default value is 0 (off/ignored).

    test

  5. Type done to save your configuration.

Session-agent Attribute

To configure the session-agent attribute and enable session recording:

  1. In Superuser mode, type configure terminal and press Enter.
    ORACLE# configure terminal
  2. Type session-router and press Enter to access the session router-related objects.
    ORACLE(configure)# session-router
    ACMEPACKET(session-router)#
  3. Type session-agent and press Enter to access the session agent-related attributes.
    ORACLE(session-router)# session-agent
    ORACLE(session-agent)#

  4. session-recording-server — Enter a space-separated list containing up to four names of session-recording-servers, or session-recording-groups, or a combination of both to apply to the session recording client (Oracle® Enterprise Session Border Controller). For each entry, use '+' to add, '-' to remove, omit to replace list. For example, (session-agent)# session-recording-server "+srs1 +srs2 -srs4 +SRG:srg1". Enter a ? to view a list of all acceptble name formats. Press the TAB key after the session-recording-server to view a list of configured SRSs and SRGs. Valid values are alpha-numeric characters. Default is no value specified.
    Do not use the format +srs1 -srs1. In this case, srs1 is still retained even after using -srs1 in the command.
    ORACLE(session-agent)# session-recording-server <srs-name>

    or

    ORACLE(session-agent)# session-recording-server SRG:<group-name>

    Note:

    The value for this attribute is the name you specified the session-recording-server attribute. If specifying a session-recording-group, you must precede the group name with SRG:.
  5. session-recording-required — Enter whether or not you want a call to be accepted by the Oracle® Enterprise Session Border Controller if recording is not available. Valid values are:
    • Enabled - Restricts call sessions from being initiated when a recording server is not available.

    • Disabled (default)- Allows call sessions to initiate even if the recording server is not available.

    ORACLE(session-agent)# session-recording-required disabled

    Note:

    Oracle recommends that the session-recording-required parameter remain disabled.
  6. Enter exit to exit the session agent configuration.
    ORACLE(session-agent)# exit
  7. Enter exit to exit the session router configuration.
    ORACLE(session-router)# exit
  8. Enter exit to exit the configure mode.
    ORACLE(configure)# exit
  9. Enter save-config to save the session agent configuration.
    ORACLE# save-config
  10. Enter activate-config to activate the session agent configuration.
    ORACLE# activate-config

Sip-interface Attribute

To configure the sip-interface attribute and enable session recording:

  1. In Superuser mode, type configure terminal and press Enter.
    ORACLE# configure terminal
  2. Type session-router and press Enter to access the session router-related objects.
    ORACLE(configure)# session-router
    ORACLE(session-router)#
  3. Type sip-interface and press Enter to access the SIP interface-related attributes.
    ORACLE(session-router)# sip-interface
    ORACLE(sip-interface)#

  4. session-recording-server — Enter a space-separated list containing up to four names of session-recording-servers, or session-recording-groups, or a combination of both to apply to the SIP interface on the session recording client ( Oracle® Enterprise Session Border Controller). For each entry, use '+' to add, '-' to remove, and omit to replace the list. For example, (sip-interface)# session-recording-server "+srs1 -srs2 +srs4 SRG:srg1". Enter a ? to view a list of all acceptble name formats. Press the TAB key after the session-recording-server to view a list of configured SRSs and SRGs.Valid values are alpha-numeric characters. Default is no value specified.
    Do not use the format +srs1 -srs1. In this case, srs1 is still retained even after using -srs1in the command.
    ORACLE(sip-interface)# sessio-recording-server SRG:<"session recording server names or session-recording group name>

    Note:

    The value for this attribute is the name you specified in the session-recording-server attribute.
  5. session-recording-required — Enter whether or not you want a call to be accepted by the Oracle® Enterprise Session Border Controller if recording is not available. Valid values are:
    • Enabled - Restricts call sessions from being initiated when a recording server is not available.

    • Disabled (default)- Allows call sessions to initiate even if the recording server is not available.

    ORACLE(sip-interface)# session-recording-required disabled

    Note:

    Oracle recommends that the session-recording-required parameter remain disabled.
  6. Enter exit to exit the SIP interface configuration.
    ORACLE(sip-interface)# exit
  7. Enter exit to exit the session router configuration.
    ORACLE(session-router)# exit
  8. Enter exit to exit the configure mode.
    ORACLE(configure)# exit
  9. Enter save-config to save the SIP interface configuration.
    ORACLE# save-config
  10. Enter activate-config to activate the SIP interface configuration.
    ORACLE# activate-config

SIPREC Ping

This SIPREC ping is a signal that the Oracle® Enterprise Session Border Controller transmits to the connected SRS requesting a response pertaining to the message type that you specify for the ping-method. It uses the ping-interval to determine how long it should wait before sending another ping to the SRS.

You can check the connectivity by configuring the following parameters:

  • Ping method- SIP message or method for which to ping the SRS.
  • Ping interval- Amount of time, in seconds, that the Oracle® Enterprise Session Border Controller waits before it pings the SRS in subsequent intervals. For example, if this parameter is set for 60 seconds, the Oracle® Enterprise Session Border Controller pings the SRS every 60 seconds.

Once configured the Oracle® Enterprise Session Border Controller uses this feature to perform SIP-based pinging to determine if the SRS is reachable or not.

Configuring SIPREC Ping on theOracle® Enterprise Session Border Controller.

To configure SIPREC ping on the Oracle® Enterprise Session Border Controller, you use the ping-method and the ping-interval objects under call-recording-server. Use the following procedure to configure SIPREC ping on the Oracle® Enterprise Session Border Controller.

To configure SIPREC ping:

  1. In Superuser mode, type configure terminal and press Enter.
    ACMEPACKET# configure terminal
    ACMEPACKET(configure)#
  2. Type session-router and press Enter.
    ACMEPACKET(configure)# session-router
    ACMEPACKET(session-router)#
  3. Type call-recording-server and press Enter.
    ACMEPACKET(session-router)# call-recording-server
    ACMEPACKET(call-recording-server)#
  4. ping-method—Enter the message or method type for which the Net-Net ESD uses in a ping request to the SRS to determine if it is reachable or not. Default is blank. Valid values are:
  5. ping-interval—Enter the amount of time, in seconds, that the Net-Net ESD waits before it pings the SRS in subsequent intervals. Valid values are 0 to 99999. Default is 0 (zero). The setting of zero disables the ping interval.
  6. Type done and press Enter.
    ACMEPACKET(call-recording-server)# done
    ACMEPACKET(call-recording-server)#
  7. Type exit and press Enter.
    ACMEPACKET(call-recording-server)# exit
    ACMEPACKET(session-router)#
  8. Type exit and press Enter.
    ACMEPACKET(session-router)# exit
    ACMEPACKET(configure)#
  9. Save the configuration.

Example SIPREC Ping Configuration

The following is an example of a SIPREC ping configuration.

call-recording-server# show
     name                 SRS1
     description          session recording server
     realm                realmA
     mode                 selective
     destination          132.43.5.6
     port                 5060
     transport-method     DynamicTCP
     ping-method          OPTIONS
     ping-interval        60

In the above example, the Net-Net ESD sends a ping request to the SRS using the OPTIONS value every 60 seconds to determine if the SRS is reachable or not.