Step, Description | Cisco Systems ATA 188 guide

Appendix D H.323 Signaling

H.323 Signaling Scenarios

Table D-3 Action Descriptions

	Step	Action			Description

1.		Local Admission Request (ARQ)—Local H.323			Cisco ATA sends a local ARQ message to the H.323
		endpoint to H.323 gatekeeper			gatekeeper seeking authorization to place a call over the
					H.323 network.

2.		Local Admission Confirm (ACF) or Admission			H.323 gatekeeper returns a ACF or ARJ message, indicating
		Reject (ARJ)—H.323 gatekeeper to the local H.323			whether or not the responding gatekeeper is going to allow
		endpoint			the Cisco ATA device access to the network.

3.		Open TCP Channel for Q.931 messaging			TCP port 1720 is opened, making way for the forward and
					reverse flow of Q.931 signaling messages between the H.323
					endpoints.

4.		Q.931		Call Setup—Local H.323 endpoint to remote	Call setup initiates from the local H.323 endpoint.
		H.323 endpoint

5.		Q.931		Call Proceeding—Remote H.323 endpoint to	Remote H.323 endpoint acknowledges call setup initiation.
		local H.323 endpoint

6.		Remote Admission Request (ARQ)—Remote			(Somewhat simultaneous, chronologically, to call setup and
		Cisco ATA to H.323 gatekeeper			call proceeding) remote H.323 endpoint contacts the common
					H.323 gatekeeper, seeking authorization to complete the
					two-way H.323 network call.

7.		Remote Admission Confirm (ACF) or Admission			H.323 gatekeeper returns a ACF or ARJ message, indicating
		Reject (ARJ)—H.323 gatekeeper to the remote			whether or not the responding gatekeeper is going to allow
		Cisco ATA			the Cisco ATA device access to the network.

8.		Q.931		Alerting—Remote H.323 endpoint to local	Status message is sent to calling H.323 endpoint advising that
		H.323 endpoint			the called party has been notified (phone ringing).

9.		Q.931		Connect—Remote H.323 endpoint to local	Status message is sent to calling H.323 endpoint advising that
		H.323 endpoint			the called party has answered the call (phone off hook).

10.		Open TCP Channel for H.245			Dynamically assigned TCP port is opened on both the local
					and remote H.323 endpoints, allowing for subsequent call
					setup activities (transmission and reception capability
					exchange, master-slave relationship determination, and so
					on).

11.		H.245		Terminal Capabilities	Various endpoint transmission and reception capabilities
					defining operation of voice, video, and data are exchanged
12.		H.245		Terminal Capabilities
					and acknowledged to ensure consistent, reliable two-way

13.		H.245		Terminal Capabilities
					communication between endpoints.

14.		H.245		Terminal Capabilities

15.		Exchange of Master-Slave Determination			Determines master and slave assignments between H.323
		Messages—Remote H.323 endpoint to local H.323			endpoints.
		endpoint

16.		H.245		Open Audio Logical Channel—Local H.323	Before actual transmission or reception of voice, video, or
		endpoint to remote H.323 endpoint			data, notification that the primary logical channel for the
					local H.323 endpoint has been opened, ensuring clear
					two-way communication.

17.		H.245		Open Audio Logical Channel	Remote H.323 endpoint acknowledges readiness.
		Acknowledgement—Remote H.323 endpoint to local
		H.323 endpoint

			Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (H.323)

	D-6				OL-4008-01

ATA 188 specifications

The Cisco Systems ATA 188 is a versatile Analog Telephone Adapter designed to facilitate the integration of traditional telephone systems with Voice over Internet Protocol (VoIP) networks. This device has been key in bridging the gap between legacy telephony and modern IP-based communication, allowing users to leverage their existing analog phones while enjoying the benefits of digital connectivity.

One of the main features of the ATA 188 is its ability to connect regular analog phones to a VoIP network, enabling users to make and receive calls over the internet. This significantly reduces calling costs, especially for long-distance and international calls. The ATA 188 supports two phone lines, allowing simultaneous voice calls. This dual-line capability makes it a suitable choice for small businesses or home offices that require multiple lines without the need for extensive infrastructure.

The device is equipped with various technologies that enhance its functionality. It supports the Session Initiation Protocol (SIP) and H.323, making it compatible with a wide range of VoIP service providers. Additionally, the ATA 188 features Quality of Service (QoS) settings, which prioritize voice traffic over the internet, ensuring clear voice quality without interruptions or delays. This is essential for maintaining a professional communication experience, especially in business environments.

Another characteristic of the ATA 188 is its user-friendly configuration interface. It allows users to easily set up and manage their devices through a web-based portal. The configuration process is straightforward, with options to adjust settings such as codec selection, call features including call waiting, and call forwarding functionalities.

Security is also a priority for the ATA 188, as it provides robust protocols to protect call data. The device supports Secure Real-time Transport Protocol (SRTP) and Transport Layer Security (TLS) to encrypt voice traffic and manage signaling securely. This ensures that sensitive conversations remain confidential.

Overall, the Cisco Systems ATA 188 is a reliable and efficient solution for users looking to transition from traditional telephony to VoIP. Its dual-line capacity, compatibility with multiple VoIP standards, user-friendly configuration, and built-in security features make it a valuable asset for both personal and professional communication solutions. In an ever-evolving telecommunications landscape, the ATA 188 remains a relevant and practical choice for integrating legacy telephony with modern internet-based services.

Cisco Systems ATA 188 manual Step, Description

Models: ATA 188

Step

Description

OL-4008-01

ATA 188 specifications