Which service acts as a gateway to a communication network, primarily focusing on voice transmission?

The service that acts as a gateway to a communication network, specifically concentrating on voice transmission, is VoIP (Voice over Internet Protocol). VoIP technology enables voice communication to be transmitted over the internet or other IP-based networks. It converts voice signals into digital data packets that can be transmitted over the network, allowing for efficient and cost-effective communication.

VoIP serves as a bridge between traditional telephone systems and modern digital communication, offering services such as call routing, voicemail, and video calls. This capability to facilitate voice communication over data networks highlights its role as a crucial gateway within communication networks, particularly since it supports both local and long-distance calls without the constraints of traditional circuit-switched telephony.

In contrast, services like the Internet provide a broader network infrastructure for various types of data transfer—including but not limited to voice. E-LAN and E-Line are services associated with Ethernet networking but do not specifically target voice transmission as their primary function. E-LAN allows for any-to-any connectivity, while E-Line typically offers point-to-point services, neither of which focus primarily on voice traffic. Thus, VoIP stands out as the most relevant service for voice transmission in this context.