Log in
|
How to Buy
|
Contact Us
|
United States (Change)

## Choose Country

### North America

- United States

### Europe

- Deutschland - Germany
- España - Spain
- France
- Italia - Italy
- Россия - Russia
- United Kingdom

### Asia Pacific

- Asean Region (Vietnam, Indonesia, Singapore, Malaysia)
- Australia
- 中国 - China
- India
- 日本 - Japan
- 대한민국 - Korea
- 台灣 - Taiwan

Remember my choice

# Technical Documentation

Download Software
Research a Problem
Case Management
Contract & Product Management
Technical Documentation
Documentation Archive
Report Documentation Bug
Enterprise MIBs
File Format Help
Glossary
Portable Libraries
End-of-Life Products
Contact Support
Guidelines and Policies
Security Resources
Feedback

## Documentation Search

Advanced Search | Search Tips

## Related Documentation

- Configuring Bundle Failover Between CTP Devices at the Same Site

# Bundle Failover Between CTP Devices at the Same Site Overview

Y-cable redundancy provides bundle failover using CTP devices at the same site. It provides a way to back up a CTP device with a redundant device at the same site, which increases circuit availability to a site (typically a remote site). The purpose of this redundancy scheme is to maximize network availability by providing complete hardware redundancy that protects from failures that include the network, chassis, processor, power supplies, and the interface module. It quickly restores communications when a system is not reachable or has failed, and is especially valuable at locations that do not have maintenance personnel or spare parts.

As shown in Figure 1, during a network or equipment failure, the affected circuit is switched to a co-located alternate CTP device and port. The process of switching the circuit to the redundant system is controlled by the AutoSwitch feature running at the hub CTP system. You need to configure AutoSwitch at the CTP hub location.

Figure 1: Autoswitch with Y-Cable Redundancy

To use this feature, you use a Y cable to connect the active and standby CTP devices. With this feature enabled, the active CTP device passes data and generates keepalive messages with the standby CTP device over the Y-cable. If a failure occurs, the standby CTP device becomes active and transmits data on the circuit.

## Requirements for Y-Cable Redundancy

Keep the following in mind when you use Y-cable redundancy:

- Y-cable redundancy is supported only on serial interfaces. The serial interface cannot have a T1/E1 daughter card installed.
- This feature requires a special Y cable. The Y cable provides control leads between the two CTP devices in addition to the standard signal, clock, and data leads connected to the attached device. There is one Y cable for CTP2000 devices and another Y cable for CTP150 devices. Therefore, you must use the same platform type at each site.
- The Y cable is short to maintain signal quality. The two CTP devices connected to the Y cable must be in close proximity to each other.
- To run diagnostics on a nonactive bundle attached to a Y cable without introducing data errors on the active bundle, Y-cable redundancy must be configured, and you cannot have a daughter card installed.

## Clocking Supported with Y-Cable Redundancy

Y-cable redundancy is supported with the following clock configurations:

- Configured rate without external TX clock (TT).
- Configured rate with external TX clock (TT).
- All clocked with external TX clock (TT).
- Adaptive clocking with internal clock.
- Adaptive clocking with external TX clock (TT).

## Related Documentation

- Configuring Bundle Failover Between CTP Devices at the Same Site

#### Published: 2010-10-26

﻿
Site Map / RSS Feeds / Careers / Accessibility / Feedback / Privacy & Policy / Legal Notices
Copyright© 1999-2011 Juniper Networks, Inc. All rights reserved.
Help
|
My Account
|
Log Out