> For the complete documentation index, see [llms.txt](https://prosbcdocs.telcobridges.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://prosbcdocs.telcobridges.com/telecom-references/protocols/link-statistics.md). # Link Statistics The following link-related statistics are available for query/display: * The **Number of changeover transmit** counter indicates the number of changeover orders transmitted for this link * The **Number of changeover received** counter indicates the number of changeover orders received for this link * The **Number of changeover acknowledgment transmit** counter indicates the number of changeover acknowledgments transmitted for this link * The **Number of changeover acknowledgment received** counter indicates the number of changeover acknowledgments received for this link * The **Number of changeback transmit** counter indicates the number of changeback declarations transmitted on this link * The **Number of changeback received** counter indicates the number of changeback declarations received on this link * The **Number of changeback acknowledgment transmit** counter indicates the number of changeback acknowledgments transmitted for this link * The **Number of changeback acknowledgment received** counter indicates the number of changeback acknowledgments received for this link * The **Number of emergency changeover transmit** counter indicates the number of emergency changeover transmitted for this link * The **Number of emergency changeover received** counter indicates the number of emergency changeover received for this link * The **Number of emergency changeover acknowledgment transmit** counter indicates the number of emergency changeover acknowledgment transmitted for this link * The **Number of emergency changeover acknowledgment received** counter indicates the number of emergency changeover acknowledgments received for this link * The **Number of link inhibit transmit** counter indicates the number of link inhibits transmitted for this link * The **Number of link inhibit received** counter indicates the number of link inhibits received for this link * The **Number of link inhibit acknowledgment transmit** counter indicates the number of link inhibit acknowledgments transmitted for this link * The **Number of link inhibit acknowledgment received** counter indicates the number of link inhibit acknowledgments received for this link * The **Number of link inhibit denied transmit** counter indicates the number of link inhibit denied transmitted for this link * The **Number of link inhibit denied received** counter indicates the number of link inhibit denied received for this link * The **Number of link uninhibit transmit** counter indicates the number of link uninhibits transmitted for this link * The **Number of link uninhibit received** counter indicates the number of link uninhibits received for this link * The **Number of link uninhibit acknowledgment transmit** counter indicates the number of link uninhibit acknowledgments transmitted for this link * The **Number of link uninhibit acknowledgment received** counter indicates the number of link uninhibit acknowledgments received for this link * The **Number of link force uninhibit transmit** counter indicates the number of link force uninhibits transmitted for this link * The **Number of link force uninhibit received** counter indicates the number of link force uninhibits received for this link * The **Number of local link inhibit test transmit** counter indicates the number of local link inhibit tests transmitted for this link * The **Number of local link inhibit test received** counter indicates the number of local link inhibit test received for this link * The **Number of remote link inhibit test transmit** counter indicates the number of remote link inhibit test transmitted for this link * The **Number of remote link inhibit test received** counter indicates the number of remote link inhibit test received for this link. * The **Number of link connection order transmit** counter indicates the number of link connection order transmitted for this link * The **Number of link connection order received** counter indicates the number of link connection order received for this link * The **Number of link connection acknowledgment transmit** counter indicates the number of link connection acknowledgment transmitted for this link * The **Number of link connection acknowledgment received** counter indicates the number of link connection acknowledgment received for this link * The **Number of link test transmit** counter indicates the number of signaling link test message transmitted on this link * The **Number of link test received** counter indicates the number of signaling link test messages received on this link * The **Number of link test acknowledgment transmit** counter indicates the number of signaling link test acknowledgment messages transmitted on this link * The **Number of link test acknowledgement received** counter indicates the number of signaling link test acknowledgement messages received on this link * The **Number of transmit MSU dropped** counter. A message to be transmitted cannot be sent and consequently is dropped. This may occur for the following reasons: * There is an error in encoding the message * The size of the message is illegal * The link is congested and a message is a COO or ECO. Changeover messages are not queued, as congestion abatement at a later time may bring down the link for which the changeover was previously sent * A message retrieved from layer 2 during changeover cannot be decoded or contains an illegal field * The **Number of transmit MSU dropped due to congestion** counter indicates the number of MSUs dropped because of congestion on this link * The **Number of SIF byte transmit** counter indicates the number of SIF octets transmitted on this link * The **Number of SIF byte received** counter indicates the number of SIF octets received on this link. * The **Number of SIO byte transmit** counter indicates the number of SIO octets transmitted on this link * The **Number of SIO byte received** counter indicates the number of SIO octets received on this link * The **Number of MSU transmit** counter indicates the number of MSUs transmitted on this link * The **Number of MSU received** counter indicates the number of MSUs received on this link * The **Number of link congestion set level 1** counter indicates the number of link congestion set at threshold 1 * The **Number of link congestion set level 2** counter indicates the number of link congestion set at threshold 2 * The **Number of link congestion set level 3** counter indicates the number of link congestion set at threshold 3 * The **Number of link unavailability** counter indicates the duration of link unavailability, expressed in milliseconds * The **Number of link congested** counter indicates the duration of link congestion, expressed in milliseconds * The **Number of invalid PDU received** counter indicates the number of invalid PDU received on this link. This may reflect one of the following conditions: * There is an error in encoding the message * PDU has a wrong size. That is, less than the minimum allowed or more than the maximum allowed * Length of PDU cannot be found * PDU cannot be decoded * PDU contains illegal SLS value * PDU is received in an invalid link state --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://prosbcdocs.telcobridges.com/telecom-references/protocols/link-statistics.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.