Commands for Verifying Voice Connections
This section describes the commands you use to verify voice connections in the MGX network:
tstconTests a connection's continuity
tstdelayTests a connection's continuity and the round-trip delay
dspconcntLists a channel's statistics counters
dspmngcidcntLists an endpoint's managed CID counters
Test Connection Command
The tstcon command tests continuity on MGX network connections. If connection segments are failed or misconfigured, the tstcon command fails. The tstcon command does not test quality of service or connectivity beyond the MGX network.
Here is the tstcon command syntax:
tstcon <channel number>
The tstcon command has some limitations:
It works only for local connections or connections in a tiered MGX network with BPX or MGX 8850-PXM45 backbone switches.
It should be issued from both ends to completely verify connectivity.
A passing result of the test does not guarantee the connection's end-to-end performance.
Test Delay Command
The tstdelay command is similar to the tstcon command in that it checks connection continuity. The tstdelay command also measures the round-trip delay through the network. The results are output on the CLI. The most recent delay measurement is also reported in the dspcon output.
Here is the tstdelay command syntax:
tstdelay <channel number>
The tstdelay output is shown in Example 22-12.
Example 22-12 tstdelay Output
smoke.1.3.VISM8.a > tstdelay 131 test type is..... 2 TestDelay in progress. TestDelay Passed with 54 us.
The limitations on the tstcon command also apply to the tstdelay command.
Display Connection Count Command
The dspconcnt command lists historical connection statistics counters on the VISM. Use this command to learn how much traffic has been sent, received, or dropped on the voice connection. The cells reported in the dspconcnt output are counted at the segmentation and reassembly (SAR) processor in the VISM. Example 22-13 shows the dspconcnt output.
Example 22-13 dspconcnt Output
smoke.1.3.VISM8.a > dspconcnt 131 ChanNum: 131 Chan State: okay Chan XMT ATM State: Normal Chan RCV ATM State: Normal OAM Lpb Lost Cells: 0 AAL2 HEC Errors: 0 AAL2 CRC Errors: 0 AAL2 Invalid OSF Cells: 0 AAL2 Invalid Parity Cells: 0 AAL2 CPS Packet Xmt: 70327 AAL2 CPS Packet Rcv: 124971 AAL2 Invalid CID CPS: 0 AAL2 Invalid UUI CPS: 0 AAL2 Invalid Len. CPS: 0 AAL5 Invalid CPI: 0 AAL5 oversized SDU PDU: 0 AAL5 Invalid Len. PDU: 0 AAL5 PDU CRC32 Errors: 0 AAL5 Reassembly Timer expired PDU: 0
The dspconcnt output shows the following information:
Channel stateokay or failed.
Channel transmit ATM stateThe channel state as reported to the ATM network and the remote end of the connection. For example, if the local line fails, the connection sends Operation, Administration, and Maintenance (OAM) alarm indicator signal (AIS) cells to the remote end (VISM or ATM interface) of the connection.
Channel receive ATM stateThe channel state reported from the ATM network.
OAM loopback lost cellsThe number of cells dropped while an OAM loopback was in progress.
HEC errorsThe number of cells with incorrect header error check (HEC) values.
CRC errorsCyclic Redundancy Check errors. This is a process that is used to check the integrity of a block of data. CRC is a common method of establishing that data was received correctly.
Invalid OSF cellsThe number of cells with an invalid offset field (OSF) in the start field of the common part sublayer protocol data unit (CPS-PDU).
Invalid CID CPSThe number of cells with invalid CIDs in the CPS packet header.
Invalid UUI CPSThe number of cells with invalid User-to-User Interface (UUI) fields in the CPS packet header.
Invalid lengthThe number of cells with a payload length that does not match the length indicator (LI) in the CPS packet header.
Invalid CPIInvalid computer-to-PBX interface.
Length Indicator (LI)The number of cells with a payload length that does not match the LI in the CPS packet header.
Sequence Number (SN)The order in which the queues are serviced. It is strongly recommended that you do not change this value. 1 to 16.
Parity (P)The process of detecting whether bits of data were altered during transmission of that data.
Oversize SDU PDUOversized service data unit (interface information that is unchanged from layer to layer) protocol data unit (packet).
Invalid length PDUInvalid protocol data unit (packet) length.
PDU CRC32 errorsProtocol data unit for CRC errors.
Reassembly timer expired PDUA PDU can span multiple ATM cells. If the remainder of the PDU does not arrive within a set time period, the reassembly timer expires, and the PDU is discarded.
Display Managed CID Counter Command
Use the dspmngcidcnt command to display the managed CID count for a specified endpoint. Example 22-14 shows the dspmngcidcnt output.
Example 22-14 dspmngcidcnt Output
smoke.1.3.VISM8.a > dspmngcidcnt 50 EndptNum: 50 Lcn: 131 Cid: 9 SentPkts: 76843 RcvdPkts: 76844 SentOctets: 3301527 RcvdOctets: 3301570 LostPkts: 0 Jitter: 0 Latency: 0 Ext AIS Rcvd: 0 Ext RAI Rcvd: 0 Ext Conn AIS Rcvd: 0 Ext Conn RDI Rcvd: 0
The dspmngcidcnt output includes the following information:
Sent packetsThe number of packets sent to the network.
Received packetsThe number of packets received from the network.
Sent octetsThe number of octets sent to the network.
Received octetsThe number of octets received from the network.
Lost packetsThe number of packets lost during transmission.
JitterThe phase shift of digital pulses over a transmission medium.
LatencyThe time it takes to get information through a network; waiting time or time delay.
External AIS receivedThe number of alarm indicator signals received from the line.
External RAI receivedThe number of remote alarm indicators (RAIs) received from the line.
External connection AIS receivedAn external connection AIS has been received.
External connection RAI receivedAn external connection RAI has been received.