Specifications

Chapter 4 Troubleshooting and Diagnostics IPmux-1/1E Installation and Operation Manual
4-20 Performance Monitoring and Troubleshooting Statistics
Table 4-6. Bundle Connection Status Parameters (Cont.)
Parameter Description
Sequence
Errors
Each packet transmitted by IPmux holds a sequence number. The receiving IPmux checks
these numbers at the receive mechanism and expects to see that each new incoming packet
is “in sequence” relative to the previous one (i.e., packet no. 5 is received after no. 4).
When, for some reason, this is not the case (i.e., next packet is not in sequence relative to
the previous one), this means that there had been a problem with packet flow integrity (and
hence data/voice integrity). IPmux will indicate this by increasing the “Sequence Errors”
counter by one.
There may be two reasons for a Sequence Error notification:
• Packet or packets are lost somewhere along the network.
• Re-ordering of packets by network.
Packet re-ordering may occur due to queuing mechanisms, re-routing by the network, or
when the router updates very large routing tables.
Recommendations
:
Make sure IPmux traffic has sufficient bandwidth. See
Chapter 1 for Throughput Calculation.
Make sure Ethernet connection is functioning properly. (See
LAN Statistics above.)
Make sure Ethernet/IP network provides priority (Quality Of Service) to the IPmux traffic.
Priority may be achieved by three means: VLAN tagging, IP TOS marking or by using the
constant 2142 decimal value at the “UDP destination Port” field of each TDMoIP packet.
Verify that the IP network devices (switches/routers/modems/etc.) are capable of handling the
IPmux PPS rate (Packets Per Second). For PPS Calculations refer to
Chapter 1.
Make sure the network devices do not drop/loose/ignore packets.
Note: IPmux-1/1E may support a “reordering mechanism”, which can sort packets back to
their original order in some situations. For more details, refer to Tech Support.