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Cisco Content Delivery Engine Series

Field Notice: FN - 62742 - U.S. Daylight Savings Time Policy Changes Effective March 2007 - for Content Delivery System TV Streaming Application - Patch Update Required


March 8, 2007

NOTICE:

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.


Products Affected

Products Affected

CDE - CDS-TV 1.4

CDE - CDS-TV 1.5

Problem Description

New U.S. Daylight Savings Times rules go into effect in March 2007. Consequently, customers whose network components rely on the default U.S. summertime clock settings within Cisco Content Delivery System TV Streaming Application (CDS-TV) software will be affected by the following problem.

For operating systems that have not been updated with the new U.S. DST policy changes, timestamps will exhibit a one hour time clock offset lasting three weeks beginning at 2:00 A.M. on the second Sunday in March of 2007. They will also exhibit a one hour time clock offset lasting one week beginning at 2:00 A.M. on the first Sunday in November.

Any time-dependent product features of CDS-TV will be affected by this problem unless you upgrade the software image or apply the workaround as herein described.

Example of potential concerns:

This could cause major problems in your network. It makes troubleshooting more difficult because the log times are off by an hour. Any stream session and content ingest correlation to pitcher/catcher networks or asset management and reporting will be off for one hour in this timeframe.

Background

On August 8, 2005, the Energy Policy Act of 2005 (H.R.6.ENR), was signed into law. Section 110 of this Act modified the time change dates for Daylight Saving Time (DST) in the U.S.

Beginning in March of 2007, DST will begin on the second Sunday of March and end the first Sunday of November.

For 2007 and beyond, the daylight saving time period will be:

2:00 A.M. on the second Sunday in March

to

2:00 A.M. on the first Sunday in November

For more information on the Energy Policy Act of 2005, see H.R. 6. (See Section 110)

CDS-TV defines the summertime rules for daylight savings time in software. Patched software images for these products will use the new daylight savings time rules defined in the Energy Policy Act of 2005 (H.R.6.ENR), Section 110.

Problem Symptoms

Impact to Networking Systems

Networking systems often make use of local time to mark logs, as well as to schedule certain events, such as IP SLA schedule starts, or the beginning or end of a time-based access-list.

In addition, inconsistencies between time zone definitions may impact event correlation systems as well as other management systems relating to problem escalation. Having accurately represented local time is a very big concern for most organizations. Local time may be reflected in logs and on phone displays. This is especially true of systems that require accurate time and time stamping for proper operations.

For networking systems, the clock or clock source is often derived from a trusted chronological source such as a private or public Atomic clock, often through Network Time Protocol (NTP). NTP communicates time in Coordinated Universal Time (UTC), colloquially known as GMT, and thus is not impacted, nor is a workaround for statutory time zone changes. Local time definitions, including summertime settings are part of the configuration of most Cisco products.

Network Time Protocol (NTP) Implications

Regardless of whether or not network components are configured to use differing clock sources such as UTC and NTP, networks will be affected when clock summer-time commands are enabled with incorrect parameters.

Workaround/Solution

Using NTP is not a workaround to this problem. NTP does not carry any information about timezones or summertime settings.

Solution:

Installation of Linux system patch which has the new summertime rules is required. Cisco TAC is performing patch updates and should be contacted if this has not been completed or if not currently scheduled.

A fix has been checked into CDS-TV 1.5.1.0.0 release.

A fix has been checked into CDS-TV 1.4.4.1.3 release and release notes for this SW drop documents installation procedures.

Revision History

Revision

Date

Comment

1.0

08-MAR-2007

Initial Public Release

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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