Appendix D H.323 Signaling

H.323 Signaling Scenarios

H.323 Signaling Scenarios

This section describes call flows for the following scenarios:

H.323 Endpoint-to-Gatekeeper Registration, page D-2

H.323 Endpoint-to-Endpoint Call Setup with a Common Gatekeeper, page D-5

H.323 Call Setup from H.323 Network to Circuit Switched Network, page D-14

Each of the call flows includes a call diagram, action descriptions table, and a sample log file.

H.323 Endpoint-to-Gatekeeper Registration

Figure D-1illustrates the Cisco ATA registering with an H.323 gatekeeper. This scenario features registration with no authentication.

Figure D-1 Cisco ATA-to-H.323 Gatekeeper Registration

Endpoint

GRQ

GCF/GRJ

RRQ

RCF/RRJ

Table D-1 Action Descriptions

Gatekeeper

72855

Step

Action

Description

 

 

 

1.

Gatekeeper Request (GRQ)—Cisco ATA to

Cisco ATA sends a GRQ message to the H.323 gatekeeper to see if

 

H.323 gatekeeper

any gatekeepers are available for registration.

 

 

 

2.

Gatekeeper Confirmation (GCF) or

H.323 gatekeeper returns a GCF or GRJ message, indicating whether

 

gatekeeper Rejection (GRJ)—H.323

or not the responding gatekeeper is able to register new Cisco ATA

 

gatekeeper to Cisco ATA

devices.

 

 

 

3.

Registration Request (RRQ)—Cisco ATA to

Cisco ATA sends a RRQ message to the H.323 gatekeeper in an

 

H.323 gatekeeper

attempt to register as part of that gatekeeper’s zone.

 

 

 

4.

Registration Confirmation (RCF) or

H.323 gatekeeper returns a RCF or RRJ message, indicating whether

 

Registration Rejection (RRJ)—H.323

or not the gatekeeper will add the Cisco ATA to its zone.

 

gatekeeper to Cisco ATA

 

 

 

 

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

 

D-2

OL-4008-01

 

 

 

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Cisco Systems ATA 188 manual Signaling Scenarios, Endpoint-to-Gatekeeper Registration, Step Action Description

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.