Back-to-back User Agent. A logical entity that receives a request and processes it as a UAS. In order to determine how the request should be answered, it acts as a UAC and generates requests. See RFC 3261 for details.
Comma Separated Values. An exchange format for tabular data understood by Microsoft Excel, OpenOffice.org, and many other applications.
Network protocol for data exchange, database access, accounting and policy control, successor of Radius.
Computational model for use in transmission planning. Defined by the ITU in recommendation G.107.
An egress device is the SIP device through which the call leaves the platform.
A more formal definition: An egress call leg is one which has as source a device from the platform, and the destination IP address is from outside the platform. A device is an egress device from a call if it is the source device of an egress call leg. If the call is terminated by a gateway device, this device is also considered an egress device.
Information unit from a web server for purposes of identification and customization. It is stored by the web browser and accessed by the server during subsequent visits.
An ingress device is the SIP device through which the call enters the platform.
A more formal definition: An ingress call leg is one which has as destination a device from the platform, and the source IP address is from outside the platform. A device is an ingress device from a call if it is the destination device of an ingress call leg. If the call is created by a gateway device, this device is also considered an ingress device.
A scripting programming language most commonly used to add interactive features to web pages.
A measure of the variability over time of the latency across a network. Term generally used in the VoIP environment describing the variation in delay between packets.
Mediation Engine. The ME is the core of the Session Monitor product family running the real-time data processing and serves the frontend and interfaces.
A Context is an association between a number of Terminations. The Context describes the topology (who hears/sees whom) and the media mixing and/or switching parameters if more than two Terminations are involved in the association.
MEGACO Commands between the Media Gateway Controller and the Media Gateway are grouped into Transactions.
The Mean Opinion Score (MOS) provides a numerical indication of the perceived quality of the received media. The MOS is expressed as single number in the range of 1 to 5. MOS is always measured by humans. Software products and devices like Session Monitor Operations Monitor can only estimate it, the result being MOS-LQE (listening quality estimate).
The estimation is done based on a set of static parameters and taking into account a set of factors related to the flow of the voice packets throughout the network. The content of the packets is not deeply inspected. This can have an impact in such cases where a call is hopping over multiple media processors, resulting in multiple legs, some of which are not available to Session Monitor Operations Monitor (like foreign network segments, TDM etc). In these cases, only the maximum possible voice quality over the inspected segments is provided, rather then an absolute estimate, end-to-end.
In other words, if one of the media legs not accessible to Session Monitor Operations Monitor will degrade the quality, a processor downstream will decode the signal and re-packetize it to good parameters, but without enhancing it back, Session Monitor Operations Monitor might rate the call higher then the human listener will actually perceive it.
MOS | Quality | Impairment |
---|---|---|
5 | Excellent | Imperceptible |
4 | Good | Perceptible but not annoying |
3 | Fair | Slightly annoying |
2 | Poor | Annoying |
1 | Bad | Very annoying |
Open Systems Interconnection. A joint ISO and ITU-T standard for computer networks and communication protocols.
Packet Capture file format. Used by many network analyzers including the open source tool Wireshark. The stored messages contain TCP/UDP headers, IP header and Layer 2 headers, plus the timestamp at which the message was received.
Portable Document Format. PDF is used for representing two-dimensional documents in a manner independent of the application software, hardware, and operating system.
A probe is software that collects raw signaling data and media traffic. You can configure probes to run locally within the Mediation Engine (embedded probe), or integrated with Oracle Communications Session Border Controller (embedded probe), or run on dedicated machines (standalone probe).
An intermediary entity that acts as both a server and a client for the purpose of making requests on behalf of other clients. A proxy server primarily plays the role of routing. See RFC 3261 for details.
Remote Authentication Dial-In User Service is a networking protocol that provides centralized Authentication, Authorization, and Accounting (AAA) management for computers to connect and use a network service.
Session Border Controller. Used in some VoIP networks to offer decoupling, interoperability, and to hide the internal topology. They are typically involved in the signalling and often also relay the media streams. From the SIP point of view, they are usual B2BUAs.
Stream Control Transmission Protocol. Is a Transport Layer protocol ensuring reliable, insequence transport of messages with congestion control.
User Agent Client. The SIP element that creates a new request; usually the caller's SIP device in case of calls, or the user's SIP device in case of registrations. For details, see RFC 3261, Section 6.
User Agent Server. The SIP element answering the request; usually the callee's SIP device, or a SIP server. For details, see RFC 3261, Section 6.