Title: Sipnms
Content:  sipnms is a web-based network management tool which uses SIP (Session Initiation Protocol) to monitor remote nodes.
Title: Next Generation 9-1-1
Content:  The NG9-1-1 vision relies on 9-1-1 specific application functionality on an Emergency Services IP Network (ESInet) to deliver voice, video, text and data "calls" to the PSAP. The protocol used for delivering these "calls" will be the Session Initiation Protocol (SIP), or IP Multimedia Subsystem (IMS, which incorporates SIP). The functional and interface standards developed by NENA describe general SIP and IMS-based architectures that allow responsible 9-1-1 Authorities flexibility in developing an infrastructure to support the envisioned features of NG9-1-1.
Title: Next-generation network
Content:  to easily and consistently traverse NAT and firewall devices, opening up the possibility that H.323 may again be looked upon more favorably in cases where such devices encumbered its use previously. Nonetheless, most of the telcos are extensively researching and supporting IP Multimedia Subsystem (IMS), which gives SIP a major chance of being the most widely adopted protocol. For voice applications one of the most important devices in NGN is a Softswitch – a programmable device that controls Voice over IP (VoIP) calls. It enables correct integration of different protocols within NGN. The most important function of the Softswitch is creating the interface to the existing telephone network, PSTN, through Signalling Gateways and Media Gateways. However, the Softswitch as a term 
Title: Text over IP
Content:  Next Generation Networking (NGNs) is a concept developed by telecommunication service providers and their suppliers. It aims to create a true multi-service network based in IP technology. ToIP has been specified for inclusion in the 3GPP IP Multimedia Subsystem (IMS) (in 3GPP TS 26.114 v2.0.0 "IMS, Multimedia Telephony, Media handling and interaction"). IMS is being used to implement NGNs in many fixed and mobile networks. Support of ToIP is being considered in multimedia Emergency Public-safety answering point (PSAPs) in Europe and USA. The ECRIT IETF working group defines ToIP as one form of access to Emergency Services. ToIP can provide a 'low impact' solution to meeting national regulatory requirements to provide 'equivalent service' to the telephone service for people who have hearing or speech impairments. A typical terminal on a fixed line access is a home computer that supports multimedia communications - Voice and Video and real-time Text over IP. See External links for information about ToIP equipment and software.
Title: UMTS security
Content:  The IP multimedia subsystem (IMS) is a core network subsystem within UMTS. It is based on the use of the Session Initiation Protocol (SIP)26 to initiate, terminate and modify multimedia sessions such as voice calls, video conferences, streaming and chat. SIP is specified by the Internet Engineering Task Force (IETF)27. IMS also uses the IETF Session Description Protocol (SDP)28 to specify the session parameters and to negotiate the codecs to be used. SIP runs on top of different IP transport protocols such as the User Datagram Protocol (UDP) and the Transmission Control Protocol (TCP). A 3G IMS subscriber has one IP multimedia private identity (IMPI) and at least one IP multimedia public identity (IMPU). To participate in multimedia sessions, an IMS subscriber must register at least one IMPU with the IMS. The private identity is used only for authentication purposes.
Title: SIP extensions for the IP Multimedia Subsystem
Content:  The Session Initiation Protocol (SIP) is the signaling protocol selected by the 3rd Generation Partnership Project (3GPP) to create and control multimedia sessions with two or more participants in the IP Multimedia Subsystem (IMS), and therefore is a key element in the IMS framework. SIP was developed by the Internet Engineering Task Force (IETF) as a standard for controlling multimedia communication sessions in Internet Protocol (IP) networks, working in the application layer of the Internet Protocol Suite. Several SIP extensions have been added to the basic protocol specification in order to extend its functionality. These extensions are based on Request 
Title: IP Multimedia Subsystem
Content: Service-oriented interconnection (SoIx): The physical and logical linking of NGN domains that allows carriers and service providers to offer services over NGN (i.e., IMS and PES) platforms with control, signalling (i.e., session based), which provides defined levels of interoperability. For instance, this is the case of "carrier grade" voice and/or multimedia services over IP interconnection. "Defined levels of interoperability" are dependent upon the service or the QoS or the Security, etc. ; Connectivity-oriented interconnection (CoIx): The physical and logical linking of carriers and service providers based on simple IP connectivity irrespective of the levels of interoperability. For example, an IP interconnection of this type is not aware of the specific end to end service and, as a consequence, 
Title: SIP extensions for the IP Multimedia Subsystem
Content:  explained extensions to SIP that make it possible for the IMS to work successfully, it is also necessary that the IMS framework interworks and exchanges services with existing network infrastructures, mainly the Public switched telephone network (PSTN). There are several standards that address this requirements, such as the following two for services interworking between the PSTN and the Internet (i.e. the IMS network): And also for PSTN-SIP gateways to support calls with one end in each network: Moreover, the SIP INFO method extension is designed to carry user information between terminals without affecting the signaling dialog and can be used to transport the dual-tone multi-frequency signaling to provide telephone keypad function for users.
Title: GNU SIP Witch
Content:  GNU SIP Witch is a free SIP server software with Peer-to-peer capabilities from the GNU Project. It is the GNU implementation of the Session Initiation Protocol (SIP), which is being used for the routing of the calls.
Title: SIP extensions for the IP Multimedia Subsystem
Content: PSTN Interworking Service Protocol (PINT), that extends SIP and SDP for accessing classic telephone call services in the PSTN (e.g. basic telephone calls, fax service, receiving content over the telephone). ; Services in PSTN requesting Internet Services (SPIRITS), that provides the opposite functionality to PINT, this is, supporting the access to Internet services from the PSTN. Session Initiation Protocol for Telephones (SIP-T), that describes the practices and uses of these gateways. ; ISDN User Part (ISUP) to Session Initiation Protocol (SIP) Mapping, which makes it possible to translate SIP signaling messages into ISUP messages of the Signaling System No. 7 (SS7) which is used in the PSTN, and vice versa. Apart from all 

Question: what does sip stand for in the ngn / ims context?
Answer: Session Initiation Protocol.