Cisco Active Network Abstraction Reference Guide, 3.7
TDM/DSx

Table Of Contents

TDM/DSx

Technology Description

TDM

DSx

T3/E3

Channelized T3, OC3, DS3 Interface

Circuit Emulation over MPLS

1588 Clocking

SyncE Clocking

Information Model Objects (IMOs)

DS0 Bundle Interface

DS1 Physical

DS3 Physical

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

Network Topology

Service Alarms


TDM/DSx


This chapter describes the level of support that Cisco ANA provides for time-division multiplexing (TDM), Digital Signal (DSx) Hierarchy, and related physical technologies, as follows:

Technology Description

Information Model Objects (IMOs)

Vendor-Specific Inventory and IMOs

Network Topology

Service Alarms

Technology Description

TDM

Time-Division Multiplexing (TDM) is a type of digital multiplexing in which two or more signals or bit streams are transferred apparently as subchannels in one communication channel. The transmission of these streams appears to be simultaneous, but they are actually taking turns on the channel. This is done by dividing the transmission time domain into several recurrent slots of fixed length, one for each subchannel. A sample byte or data block of subchannel 1 is transmitted during timeslot 1, subchannel 2 during timeslot 2, and so on. One TDM frame consists of one timeslot per subchannel. After the last subchannel, the cycle starts again with a new frame, starting with the second sample, byte or data block from subchannel 1, and so on.

DSx

Digital Signal (DSx) Hierarchy refers to the rate and format of digital telecommunication circuits, as part of the North American Digital Hierarchy. DSx is related to the T-carrier designations. However, DS refers to multiplexing techniques, while the T designations refer to the underlying equipment and signaling. There are various DS levels, the most common being:

DS0/Fractional T1 (64 Kb/s), which represents a single voice telephone call.

DS1/T1 (1.544 Mb/s), with 24 user channels.

DS2/T2 (6.312 Mb/s), with 96 user channels.

DS3/T3 (44.736 Mb/s), with 672 user channels.

T3/E3

T-carrier telecommunications is a generic name for several digitally multiplexed telecommunications carrier systems used in North America, Japan, and Korea. The basic unit of the T-carrier system is the Fractional T1, which corresponds to the Digital Signal Hierarchy's DS0, and is commonly used for one voice circuit.

The E-carrier system (the "E" stands for "European") is incompatible with the T-carrier system (though cross-compliant cards exist). It is in common use everywhere outside of North America, Japan, and Korea. It typically uses the E1 (2.048 Mb/s) and E (334.368 Mb/s) line rates.

Channelized T3, OC3, DS3 Interface

Channelization, coupled with native edge-aggregation services such as MPLS and QoS, allows service providers and large enterprises to save dramatically on power, floor space, local-loop charges, and equipment costs, by permitting receipt and transmission of multiplexed T3, OC3 and DS 3 circuits over high-bandwidth physical media.

Circuit Emulation over MPLS

In CEM, TDM bitstream connections (T1, E1, T3, E3) are encapsulated as pseudowires over the MPLS backbone. Both structured and structure-agnostic TDM bitstreams are supported.

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.


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


Information Model Objects (IMOs)

This section describes the following IMOs:

DS0 Bundle Interface (IDS0Bundle)

DS1 Physical (IDS1Pdh)

DS3 Physical (IDS3Pdh)

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)

DS0 Bundle Interface

The data link layer DS0 Bundle Interface object is bound by its Containing Termination Points attribute to either DS1 Physical or DS3 Physical Layer objects. It is accessed primarily by the data link layer object, such as the ATM Interface and the Frame Relay Interface, bound by its Contained Connection Termination Points attribute.

Table 29-1 DS0 Bundle Interface (IDS0Bundle)  

Attribute Name
Attribute Description
Scheme
Polling Interval

Bundled Time Slots

Bundled time slots (DS1 channels).

Product

Configuration

Bundle Location

Bundle location/index.

Product

Configuration

AdminStatus

The administrative status of the interface (Down, Testing, Up).

IPCore

Configuration

OperStatus

The operational status of the interface (Down, Testing, Up).

IPCore

Configuration

IANA Type

Internet Assigned Numbers Authority (IANA) type of the sublayer.

N/A

N/A

Containing Termination Points

Underlying termination points (connection or physical).

Product

N/A

Contained Connection Termination Points

Bound connection termination points.

Product

N/A


DS1 Physical

The physical layer DS1 Physical and DS3 Physical objects are bound by their Containing Termination Points attribute to a Port Connector object. Each of these objects is accessed primarily by the data link layer object (such as an ATM Interface, Frame Relay Interface, or DS0 Bundle Interface) bound by its Contained Connection Termination Points attribute.

Table 29-2 DS1 Physical (IDS1Pdh)  

Attribute Name
Attribute Description
Scheme
Polling Interval

Framing Type

Framing type (Null, OTHER, ESF, ANSI ESFf, D4, E1, E1 CRC, E1 MF, E1 CRC MF, UNFRAMED, E1 UNFRAMED, DS2 M12, E2, E1 Q50, E1 Q50 CRC, ANSI SF, E1 CAS CRC4, E1 CAS No CRC4, E1 No CAS CRC4, E1 No CAS No CRC4, E1 Unstructured, T1 Unstructured, CLEAR CHANNEL).

Product

Configuration

Cell Mapping Type

Cell mapping type (Null, PLCP, HEC, HCS, Direct, ADM).

Product

Configuration

Loop Back Type

Loopback type (Null, Cell, Payload, Diag, Line, None, Other, Path, Metalic, Non Metalic, Serial, Parallel, Local, Internal, Network, Inward, Dual, Remote, Inbound Local, No Loop).

Product

Configuration

Scrambling Mode

Scrambling mode (Null, On, Off).

Product

Configuration

Port Description

Port description.

Product

Configuration

International Bit

Indicates whether the E3 international bit is set.

Product

Configuration

Line Code

Line-code type for T1 or E1 lines (ami, b8zs, hdb3).

Product

Configuration

Cable Length

Set cable length.

Product

Configuration

Recovered Clocking ID

Recovered clocking ID.

Product

Configuration

Clocking

Clocking type (stratum1, and so on).

Product

Configuration

Loopback

Transponder loopback setting (none, internal, line).

Product

Configuration

All additional attributes are the same as Physical Layer (IPhysicalLayer)


DS3 Physical

Table 29-3 DS3 Physical (IDS3Pdh)  

Attribute Name
Attribute Description
Scheme
Polling Interval

Framing Type

Framing type (Null, Other, M23, SYNTRAN, CBIT, Clear Channel, E3 Other, E3 Framed, Unframed, E3 Unframed, ITU-T G.804, ITU-T G.832, M13).

Product

Configuration

Cell Mapping Type

Cell mapping type (Null, PLCP, HEC, HCS, Direct, ADM).

Product

Configuration

Loop Back Type

Loopback type (Null, Cell, Payload, Diag, Line, None, Other, Path, Metalic, Non Metalic, Serial, Parallel, Local, Internal, Network, Inward, Dual, Remote, Inbound Local, No Loop).

Product

Configuration

Scrambling Mode

Scrambling mode (Null, On, Off).

Product

Configuration

Port Description

Port description.

Product

Configuration

International Bit

Indicates whether the E3 international bit is set.

Product

Configuration

Line Code

Line-code type for T1 or E1 lines (ami, b8zs, hdb3).

Product

Configuration

Cable Length

Set cable length.

Product

Configuration

Recovered Clocking ID

Recovered clocking ID.

Product

Configuration

Clocking

Clocking type (stratum1, and so on).

Product

Configuration

Loopback

Transponder loopback setting (none, internal, line).

Product

Configuration

All additional attributes are the same as Physical Layer (IPhysicalLayer)


CEM Interface

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

Table 29-4 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 29-5 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 29-6 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 29-7 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 29-8 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 29-9 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 29-10 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 29-11 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 29-12 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 configuation for a single interface on an NE.

Table 29-13 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.

Network Topology

Cisco ANA does not support discovery of physical layer topology. This topology is manually (statically) configured by the system administrator. However, it is used in conjunction with the data link layer above it, such as ATM, for discovering its physical topology, while further verifying it by matching the traffic signature of these ports using Cisco's confidential scheme, which requires a substantial amount of traffic in order to function correctly.

Service Alarms

The following alarms are supported for this technology:

Discard Input Packets/Normal Discard Input Packets

Dropped Output Packets/Normal Dropped Output Packets

Link Down/Link Up

Port Down/Port Up

Receive Utilization/Receive Utilization Normal

Transmit Utilization/Transmit Utilization Normal

DS0 Bundle Admin Down

DS0 Bundle Oper Down

DS0 Bundle Up

For detailed information about alarms and correlation, see the Cisco Active Network Abstraction 3.7 User Guide.