Cisco MCS-7825-H3-IPC1 Service Guide - Page 252

Cisco Unified Serviceability Alarms and CiscoLog Messages Chapter 6 Cisco Unified Serviceability Alarms and CiscoLog Messages characters in the values of substitutable parameters, it is recommended that the value at least does not include unbalances brackets (like an opening bracket without a closing one). When these recommendations are followed, it would be possible to programmatically extract substitutable parameter values out of a CiscoLog message. However, this recommendation is not a strict requirement. Message text should be spell-checked. Editorial review is recommended. This includes all messages that can be seen by the customers, even debugging messages. If the first word of the message is an English word, the first letter should be capitalized. Single sentence messages do not require a period at the end. Internationalization Foreign language characters are defined as characters with ASCII decimal values 0-126. Foreign language characters are supported in the HOST field, the value part of the TAGS field and the MESSAGE field. Foreign language characters must be encoded using the Unicode standard UTF-8. UTF-8 provides encoding for any language without requiring the application to know local encoding/decoding rules for a particular language. In fact, the application encoding the message does not even need to know the language of the message. UTF-8 can encode any Unicode character. UTF-8 encodes US ASCII characters exactly as they would normally be encoded in a 7-bit ASCII convention. This means that applications interpreting CiscoLog messages can assume that entire messages are encoded in UTF-8. On the other hand, applications producing CiscoLog messages can encode the entire message using US-ASCII 7-bit convention if they are known not to support foreign languages in their products. Since UTF-8 can encode characters in any language, it is possible to mix and match languages. For example, it is anticipated that a one use-case would be the inclusion of just some parameters in foreign language in an otherwise English message. For example, an English message about user authentication could have a username in Japanese. Similarly, any number of languages can be combined in a CiscoLog message. In order to take advantage of messages, which include a foreign language, a log viewer capable of interpreting UTF-8 would be necessary. Most likely, the log viewer would also require that the appropriate language fonts be installed on a given system. In a US-ASCII only editor, the user will see garbage for non-US-ASCII characters encoded in UTF-8, but should be able to see all US-ASCII text. Internationalization support can be readily used with CiscoLog messages written to a local file. Syslog RFC 3164, however, does not currently define foreign language support. Thus, in order to take advantage of internationalization with a syslog server, one would need to use a server implementation, which was tested to correctly relay or store all 8-bits of each octet unchanged. This would ensure that UTF-8 encoded parts of the message retain all their information when foreign languages are used. In UTF-8, a single character is encoded with one or more octets. The CiscoLog message length limit is specified as 800 octets. Developers must be aware that with foreign languages, the 800-octet length limit may mean fewer than 800 characters. When a message is split into a multi-part message using guidelines provided in Multipart Messages, page 6-4, octets belonging to a single character must never be split into separate lines. Versioning CiscoLog does not provide any versioning information in the message format. Extensions to the format must be made within the restrictions of the format. CiscoLog message formats provides for extensions by way of defining additional tags. 6-18 Cisco Unified Communications Manager Managed Services Guide OL-22523-01