Ho'ākāka: SIP - Session Initiation Protocol - he protocolke kikowaena i hoʻohanaʻia no ka leo ma IP (VoIP) hōʻailona. Ma ka pūnaewele VoIP , SIP kekahi ala'ē aʻe e hōʻailona ma ka hoʻohanaʻana i nā kūlana kūlana o ka H.323 .
Ua hoʻokumuʻia ka SIP e kākoʻo i nā hiʻohiʻona koho o nā pūnaewele kelepona. Eia naʻe, likeʻole me kaʻenehana SS7 kahiko no kaʻikeʻana i ke kelepona,ʻo ka SIP he kulekele hoa-pe-hoa. ʻO ka SIP kekahi hana laulā nui no nāʻaha kūikawā i kaupalenaʻoleʻia i nā noi leo.