Table Of Contents

Clocking

Technology Description

1588 Clocking

SyncE Clocking

Adaptive Clock Recovery (ACR)

Information Model Objects (IMOs)

CEM Interface

CEM Group

Clock Service

Clock Source

PTP Service

PTP Interface

ACR Service

Recovered Clock

SyncE Service

SyncE Interface

Vendor-Specific Inventory and IMOs

Service Alarms

Clocking

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This chapter describes the level of support that Cisco ANA provides for clocking, as follows:

•Technology Description

•Information Model Objects (IMOs)

•Vendor-Specific Inventory and IMOs

•Service Alarms

Please see Part 1: Cisco VNEs in this guide for information about which devices support the various technologies.

Technology Description

This section provides the following Clocking technology descriptions:

•1588 Clocking

•SyncE Clocking

•Adaptive Clock Recovery (ACR)

1588 Clocking

TDM 1588 is known as Precision Time Protocol (PTP). The PTP standard specifies a clock synchronization protocol applicable to distributed systems consisting of one or more nodes communicating over a network. Nodes are modeled as containing a real-time clock that may be used by applications within the node for various purposes, such as generating time stamps for data or ordering events managed by the node. The protocol provides a mechanism for synchronizing the clocks of participating nodes to a high degree of accuracy and precision.

SyncE Clocking

One of the fundamental requirements placed on next-generation networks is to provide the ability to distribute precision frequency or timing synchronization around the network. Frequency synchronization is provided by SONET/SDH equipment. used in conjunction with external timing technology, such as Cesium oscillators and GPS.

As SONET/SDH equipment is replaced by Ethernet equipment, this frequency synchronization ability is required over Ethernet ports. Synchronous Ethernet (SyncE) provides SONET/SDH physical layer (POS-PHY) frequency distribution of known, common precision frequency references.

To maintain SyncE links, a set of operations messages is required. These messages provide information about the quality of the timing source being used to clock the SyncE link, ensuring that each node is always deriving timing from the most reliable source. In SONET/SDH networks, these messages are known as Synchronization Status Messages (SSM). Each timing source has a Quality Level (QL) associated with it, which gives the accuracy of the clock. This QL information is transmitted across the network via SSMs over the Ethernet Synchronization Messaging Channel (ESMC), or via SSMs contained in the SONET/SDH frames, so that devices can know the best available source with which to synchronize. To define a preferred network synchronization flow and help prevent timing loops, users can assign priority values to particular timing sources on each router. The combination of QL information and user-assigned priority levels allows each router to choose a timing source to clock its SyncE and SONET/SDH interfaces.

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Note Cisco ANA supports these technologies only in conjunction with data link layer technologies, such as ATM or PoS.

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Adaptive Clock Recovery (ACR)

ACR is an averaging process that negates the effect of random packet delay variation and captures the average rate of transmission of the original bit stream.

Information Model Objects (IMOs)

This section describes the following IMOs:

•CEM Interface (ICEMEncap)

•CEM Group (ICEMGroup)

•Clock Service (IClockService)

•Clock Source (IClockSource)

•PTP Service (IPtpService)

•PTP Interface (IPtpInterface)

•ACR Service (IACRService)

•Recovered Clock (IRecoveredClock)

•SyncE Service (ISyncE)

•SyncE Interface (ISyncEInterface)

CEM Interface

The CEM Interface object represents a CEM-encapsulated E1/T1 circuit interface.

Table 32-1 CEM Interface (ICEMEncap)  

Attribute Name	Attribute Description	Scheme	Polling Interval
cemIfName	The interface name (for example, CEM8/0/0 or Virtual-cem8/0/24).	IpCore	Configuration

CEM Group

The CEM Group object represents a CEM Group configured on a physical or virtual CEM Interface.

Table 32-2 CEM Group (ICEMGroup)  

Attribute Name	Attribute Description	Scheme	Polling Interval
ID	The DS0 bundle CEM group identifier.	IpCore	Configuration
IdlePattern	The 8-bit hexadecimal number that is transmitted on a T1 or E1 line when missing packets are detected on the PW circuit.	IpCore	Configuration
IdleCAS	When channel associated signaling (CAS) is used, the 8-bit hexadecimal signal that is sent when the CEM interface is identified as idle.	IpCore	Configuration
DeJitter	The size of the dejitter buffer in milliseconds (ms) (in the range 4-500, 4 is the default).	IpCore	Configuration
PayloadSize	The size of the payload (in bytes) for packets on the CEM interface (in the range 32-1312).	IpCore	Configuration
RTP	Indicates whether RTP compression is enabled or disabled.	IpCore	Configuration
RTPHeader	Indicates whether RTP header compression is enabled or disabled.	IpCore	Configuration
TimeSlots	The range of timeslots (DS0 channels) allotted to the CEM interface. Empty if the Structure-Agnostic TDM over Packet (SAToP) method is used.	IpCore	Configuration
Pseudowire	The name of the pseudowire configured on the CEM interface.	IpCore	Configuration
AdminStatus	The administrative status of the CEM interface (Down, Testing, Unknown, Up).	IpCore	Configuration
OperStatus	The operational status of the CEM interface (Dormant, Down, Not Present, Testing, Unknown, Up).	IpCore	Configuration

Clock Service

The Clock Service object models the generic clocking configuration and clocking features of a network element, independent of any particular timing scheme, such as PTP or Anonymous Call Rejection (ACR).

Table 32-3 Clock Service (IClockService)  

Attribute Name	Attribute Description	Scheme	Polling Interval
ActiveClockSource	The current active clock source used by the network element.	Any	Configuration
NcsMode	The network clock selection mode (revert, nonrevert, unknown). NCS is used in case of master device failure.	Any	Configuration
HoldTimeout	The network clock selection hold timeout in seconds (in the range 0-86400, -1 for no timeout).	Any	Configuration
UseStratum4	Indicates whether the Stratum4 clock is used (true) or not (false). The default is false, which means the Stratum3 clock is used.	Any	Configuration
Mode	The network element clocking mode (unknown, slave, master, hybrid).	Any	Configuration
NcsPriorityList	The network clock selection priority list.	Any	Configuration
Pseudowire Clock Recovery	An array of zero or more instances of ACR Service (IACRService).	Any	Configuration
PtpService	An array of zero or more instances of PTP Service (IPtpService).	Any	Configuration

Clock Source

The Clock Source object represents the network clock source defined in an instance of the Clock Service object.

Table 32-4 Clock Source (IClockSource)  

Attribute Name	Attribute Description	Scheme	Polling Interval
Priority	The priority of the defined clock source.	Any	Configuration
Source	The clock source.	Any	Configuration
Status	Indicates that the clock source status is valid (true) or non existent/non functional (false).	Any	Configuration
Type	The clock source type (BITS, packet-timing, sync, E1/T1).	Any	Configuration

PTP Service

The PTP Service object represents PTP (IEEE-1588) configurations on a network element at the device level.

Table 32-5 PTP Service (IPtpService)  

Attribute Name	Attribute Description	Scheme	Polling Interval
Mode	The PTP operating mode (unknown, ordinary, boundary, e2etransparent, p2ptransparent). On the Cisco MWR-2941, only ordinary is supported.	Any	Configuration
ClockId	The PTP clock ID.	Any	Configuration
Domain	The PTP domain ID (in the range 0 to 127).	Any	Configuration
Priority1	PTP clock selection priority-1 (in the range 0 to 255).	Any	Configuration
Priority2	PTP clock selection priority-2 (in the range 0 to 255).	Any	Configuration
PtpEnabled	Indicates whether PTP is enabled (true) or disabled (false).	Any	Configuration
PtpInterfaceList	An array of one or more instances of PTP Interface (IPtpInterface)	Any	Configuration

PTP Interface

The PTP Interface object represents PTP (IEEE-1588) configurations on a network element at the interface level.

Table 32-6 PTP Interface (IPtpInterface)  

Attribute Name	Attribute Description	Scheme	Polling Interval
Version	The PTP version (default is 2).	Any	Configuration
AnnounceInterval	The PTP interface announce interval (in the range 0 to 4)	Any	Configuration
AnnounceTimeout	The PTP interface announce timeout (in the range 2 to 10).	Any	Configuration
DestinationAddress	The clock destination IP address (can be null, set only when in Master mode).	Any	Configuration
SourceAddress	The clock source IP address (can be null, set only when in Slave mode).	Any	Configuration
DelayReq	The PTP interface delay request message interval.	Any	Configuration
MasterMode	The PTP communication mode in Master mode (notset, multicast, unicast, unicastnegotiation).	Any	Configuration
SlaveMode	The PTP communication mode in Slave mode (notset, multicast, unicast, unicastnegotiation).	Any	Configuration
SyncInterval	The PTP interface sync interval.	Any	Configuration
SyncLimit	The PTP interface maximum offset (in the range 1000 to 50000).	Any	Configuration
InterfaceXid	The XID of the associated interface.	Any	Configuration

ACR Service

The ACR Service object represents the pseudowire clock recovery.

Table 32-7 ACR Service (IACRService)  

Attribute Name	Attribute Description	Scheme	Polling Interval
RecoveredClockSource	The interface (slot or subslot) on which the clock recovery will occur.	Any	Configuration
RecoveredClockMode	The recovered clock mode.	Any	Configuration
CemInterface	The corresponding CEM or Virtual CEM interface instance ID.	Any	Configuration
RecoveredClockList	An array of one or more instances of Recovered Clock (IRecoveredClock).	Any	Configuration

Recovered Clock

The Recovered Clock object represents the clock information derived from the RNC or from other n-PE, P, or u-PE devices.

Table 32-8 Recovered Clock (IRecoveredClock)  

Attribute Name	Attribute Description	Scheme	Polling Interval
ClockId	The clock ID.	Any	Configuration
RecoveredClockMode	The recovered clock mode.	Any	Configuration
Port	The port number.	Any	Configuration
Cem	The CEM Group.	Any	Configuration
Status	The priority.	Any	Configuration
FrequencyOffset	The value of the frequency offset.	Any	Configuration

SyncE Service

The SyncE Service object represents the global Synchronous Ethernet configuration for a network element.

Table 32-9 SyncE Service (ISyncE)

Attribute Name	Attribute Description	Scheme	Polling Interval
synchronousMode	Enable automatic synchronization selection process.	Any	Configuration
equipmentClock	Indicates the currently selected Ethernet Equipment Clock option (EEC-Option I, EEC-Option II).	Any	Configuration
clockMode	Indicates whether Quality Level is enabled (QL-Disable, QL-Enable).	Any	Configuration
ssmOption	Indicates which of the Synchronization Status Messages (SSM) options is currently in use on the NE (ITU-T Option I, ITU-T Option II generation 1, ITU-T Option II generation 2).	Any	Configuration
esmcMode	Indicates whether Ethernet Synchronization Messaging Channel is enabled on the NE (true) or not (false).	Any	Configuration
holdOffTimer	The amount of time (in milliseconds) the NE waits before removing a source that has gone down (values in the range 0 to 50000, default is 300).	Any	Configuration
waitToRestore	The amount of time (in milliseconds) the NE waits before adding a source that has just come up (values in the range 0 to 86400).	Any	Configuration
Revertive	Indicates whether Revertive mode is enabled (true) or disabled (false) on the NE.	Any	Configuration

SyncE Interface

The SyncE Interface object represents the Synchronous Ethernet configuration for a single interface on an NE.

Table 32-10 SyncE Interface (ISyncEInterface)  

Attribute Name	Attribute Description	Scheme	Polling Interval
selectionInput	Assign the interface as a timing source to be passed to the selection algorithm.	Any	Configuration
ingressESMCMode	Indicates whether Ethernet Synchronization Messaging Channel is enabled (true) or disabled (false) for incoming QL information on the interface.	Any	Configuration
egressESMCMode	Indicates whether Ethernet Synchronization Messaging Channel is enabled (true) or disabled (false) for outgoing QL information on the interface.	Any	Configuration
ingressQLMode	Indicates whether incoming quality level information is enabled (true) or disabled (false) on the interface.	Any	Configuration
ingressQuality	Indicates the type of incoming quality level information, depending on the globally configured SSM option. For ITU-T Option I, available values are QL-PRC, QL-SSU-A, QL-SSU-B, QL-SEC, and QL-DNU. For ITU-T Option II generation 1, available values are QL-PRS, QL-STU, QL-ST2, QL-SMC, QL-ST4, QL-DUS. For ITU-T Option II generation 2, available values are QL-PRS, QL-STU, QL-ST2, QL-TNC, QL-ST3, QL-SMC, QL-ST4, QL-DUS.	Any	Configuration
egressQLMode	Indicates whether incoming quality level information is enabled (true) or disabled (false) on the interface.	Any	Configuration
egressQuality	Indicates the type of outgoing quality level information, depending on the globally configured SSM option. For ITU-T Option I, available values are QL-PRC, QL-SSU-A, QL-SSU-B, QL-SEC, and QL-DNU. For ITU-T Option II generation 1, available values are QL-PRS, QL-STU, QL-ST2, QL-SMC, QL-ST4, QL-DUS. For ITU-T Option II generation 2, available values are QL-PRS, QL-STU, QL-ST2, QL-TNC, QL-ST3, QL-SMC, QL-ST4, QL-DUS.	Any	Configuration
waitToRestore	The amount of time (in milliseconds) the interface waits before adding a source that has just come up (values in the range 0 to 86400).	Any	Configuration
holdOffTimer	The amount of time (in milliseconds) the interface waits before removing a source that has gone down (values in the range 0 to 50000, default is 300).	Any	Configuration

Vendor-Specific Inventory and IMOs

There are no vendor-specific inventory or IMOs for this technology.

Service Alarms

There are no service alarms for this technology.