Media5 Mediatrix 4104, Reference Manual, Page: 294 / 466

Chapter 18 - SIP Protocol Features Interop Parameters
272 Mediatrix 4104

To disable inclusion of this header in SIP requests:
1. In the sipInteropMIB , set the sipInteropMaxForwardsValue variable to -1 .
2. Restart the Mediatrix 4104 so that the change may take effect.
Referred-By Field
The SIP REFER method allows the referrer to provide information about the reference to the refer target by
using the referree as an intermediary. The mechanism for carrying the referrer's identity, expressed as a SIP
URI, is the
Referred-By header.
You can configure the Referred-By field used in a SIP REFER request to decide whether it contains the
permanent URL provided by the SIP stack or the address of record used when the unit registered.

To configure the Referred-By field:
1. In the sipInteropMIB , set the sipInteropReferredByConfig variable to the value you want.
Direction Attributes in a Media Stream
The Mediatrix 4104 allows you to define various direction attributes pertaining to the media stream.
Direction Attribute
You can define:

if the SDP direction attribute is present in the initial INVITE sent by the Mediatrix 4104

whether or not the direction attribute present in the SDP received from the peer is ignored

To define if the direction attribute is present:
1. In the sipInteropMIB , set the sipInteropSdpDirectionAttributeEnable variable to the proper value.
Table 171: Referred-By Field Parameters
Parameter Description
useSipStackDefault The SIP stack populates the Referred-By header field.
useLocalUrl Uses the local URL to populate the Referred-By header field.
Standards Supported • RFC 2543 – SIP: Session Initiation Protocol
• RFC 3264 – An Offer/Answer Model with Session Description
Protocol (SDP)
Table 172: SDP Direction Attribute
Parameter Description
disable No direction attribute is present in the SDP sent by the
Mediatrix 4104.
The Mediatrix 4104 ignores any direction attribute found in the
SDP received from the peer.
To put an endpoint on hold, a SDP containing a connection
address of “0.0.0.0” is sent.
The method to put a session on hold is in conformance with
RFC 2543.