| Subject | English | Spanish |
| comp., MS | Session Initiation Protocol | Protocolo de inicio de sesión (A standard signaling protocol for establishing multi-media communications sessions between two or more users over an IP network) |
| comp., MS | Session Initiation Protocol trunking | enlace troncal de Protocolo de inicio de sesión (A mechanism for connecting the voice network of an enterprise to a service provider that offers public switched telephone network (PSTN) origination, termination, and emergency services without deploying PSTN gateways) |