The following measurements report TCP, SCTP, and Network Services socket traffic, including timeout, error, packet, and byte counters. When TCP or SCTP is used in the bearer plane, these measurements are included in the L4 Client and L4 Server report tabs.
VoLTE/Vo5G nodals also have a Gm|L4 measurements report tab. The measurements are configured whenever Gm is enabled. "Gm|L4" is a subset of the L4 Client OMs, prefix "gm". In View Measurements comparing to "L4 Client", the set consists of (top-down) "Socket Ack Timeouts" to "Socket FIN ACK Messages Received". This is only on the UE (VoLTE/Vo5G nodals and IP Application node) side. IMS Node is not included.
Added TCP connection measurements for all Service Based Interfaces, including a new “Socket Window Full Events” measurement.
When any of these protocols are used in the control plane, measurements are available on the following report tabs: (not a full list)
Socket ACK Timeouts — The number of timeouts that occurred at the socket while waiting for an ACK to a previously sent message. CAUTION if (value > 0).
Socket Lost Packets — The number of times packet loss was detected by the receiving end. The L4 Client tab records packet loss from the Network Host to the MN and the L4 Server tab records packet loss from the MN to the Network Host, for example:
Packet loss is detected when a packet is received with a higher than expected sequence number, indicating that one or more packets were not received. When packets are received out of sequence, the test server can queue up to 30MB of the packets remaining in a window and process queued packets as gaps in the sequence are filled. Socket Lost Packets is incremented when an out-of-sequence packet is received and will not continue to increment with each packet received until the missing packets are received. Instead, it will save the out-of-sequence packets (except the first) into pending ACK list, after receiving re-transmission of lost packet, it will send ACK to all pending ACK List. CAUTION if (value > 0).
Socket Reordered Packets is incremented when the gap is filled and the packets are successfully processed. CAUTION if (value > 0).
Socket Duplicate Packets — The number of duplicate packets detected by the receiving end. A duplicate packet is detected when a smaller than expected sequence number is received. CAUTION if (value > 0).
Socket Reordered Packets — The number of queued packets that were successfully processed in the correct order after missing required packets were received. These packets are also recorded by Socket Lost Packets since it was not known whether they would be able to be processed at the time they were received.
Socket TCP Active Count — (Traffic) Indicates total number of the Active TCP connection alive at the moment when the measurement value was uploaded
Socket TCP Active Count — (Host)
Socket Idle Timeout — (Host and MN) - Indicates the total number of Idle Timeouts that reset the connection. Available for both client and server.
Socket Window Full Events — (Host and MN) - Indicates the total number of Socket Window Full messages. How many times such condition is encountered when upper layer application tries to send packets.
The payload byte counters record all bytes in the upper layers. When TCP or SCTP is the selected Data Protocol, the header bytes are not included in the payload byte counters. Those bytes are, however, included in the total byte counters above and the socket counters below.
Socket Payload Bytes Sent — The number of payload bytes sent by the socket. ERROR if (value == 0).
Socket Payload Bytes Received — The number of payload bytes received by the socket. ERROR if (value == 0).
Socket SCTP Link Switch Count — indicates the number of times the paths have switched.
Socket SCTP Primary Fail — indicates the number of time the primary path has failed. CAUTION if (value > 0).
Socket SCTP Secondary Fail — indicates the number of times the secondary path has failed. CAUTION if (value > 0).
Socket SCTP Active Count — (Traffic)
Socket SCTP Active Count — (Host)
Socket SYNC Messages Sent — When data traffic transport layer is TCP, count the TCP packets with SYNC flag set sent.
Socket SYNC Messages Received — When data traffic transport layer is TCP, count the TCP packets with SYNC flag set received.
Socket SYNC ACK Messages Sent — When data traffic transport layer is TCP, count the TCP packets with SYNC and ACK flags set sent.
Socket SYNC ACK Messages Received — When data traffic transport layer is TCP, count the TCP packets with SYNC and ACK flags set received.
Socket ACK Messages Sent — When data traffic transport layer is TCP, count the TCP packets with ACK flag set sent.
Socket ACK Messages Received — When data traffic transport layer is TCP, count the TCP packets with ACK flag set received.
Socket RST Messages Sent — When data traffic transport layer is TCP, count the TCP packets with RST flag set sent.
Socket RST Messages Received — When data traffic transport layer is TCP, count the TCP packets with RST flag set received.
Socket FIN Messages Sent — When data traffic transport layer is TCP, count the TCP packets with FIN flag set sent.
Socket FIN Messages Received — When data traffic transport layer is TCP, count the TCP packets with FIN flag set received.
The byte counters record the total bytes at the socket layer. In the bearer plane, this includes the payload bytes when the protocol is also the selected Data Protocol, the header bytes for each message in the message flow, and the bytes in the connection control messages. The connection measurements record the bearer plane connections initiated by the MNs.
Socket Invalid Packets — The number of invalid packets sent by the socket. CAUTION if (value > 0).
Socket Total Bytes Sent — The total number of bytes sent by the socket. ERROR if (value == 0).
Socket Total Bytes Received — The total number of bytes received by the socket. ERROR if (value == 0).
Socket Connect Count — The number connections sent by the socket.
Average Socket Connect Time — The average time, in microseconds, required to establish a socket connection.
Minimum Socket Connect Time — The minimum time, in microseconds, required to establish a socket connection.
Maximum Socket Connect Time — The maximum time, in microseconds, required to establish a socket connection.
Number of Sockets — The number of SCTP sockets established
Invalid Messages — The number of invalid SCTP messages rcvd
Send Message Failed — The number of message that failed to send on the SCTP socket
Retran Max Queued — The number times the retransmission queue has been filled
Retran OverFlowed — The number of times the retransmission queue has over flowed
Retran Sequence Not Found — The number of sequence that have no associated message in the retransmission queue
Retran Seq Not Removed — The number of message
OverFlow Max Queued — The number of time the overflow queue has been filled
OverFlow OverFlowed — The number of times the overflow queue has been overflowed (messages dropped)
OverFlow Message Requeued — The number of times a message in the overflow queue has been requeued
Malformed Mng Message Received — The number of malformed messages rcvd at the SCTP layer
Socket SCTP SRTT Count — The number SCTP SRTT messages sent by the socket.
Socket SCTP Average SRTT — The average time, in microseconds, required to send SCTP SRTT.
Socket SCTP Minimum SRTT — The minimum time, in microseconds, required to send SCTP SRTT
Socket SCTP Maximum SRTT — The maximum time, in microseconds, required to send SCTP SRTT
Socket SCTP Packets Sent — The total number of SCTP packets sent by the socket.
Socket SCTP Packets Received — The total number of SCTP packets received by the socket.
Socket SCTP Congestion L1 — The total number of SCTP Congestion L1 packets. Indicates the occurrence of fast retransmission started in SACKs. INFO if (value > 0).
Socket SCTP Congestion L2 — The total number of SCTP Congestion L2 packets. Indicates the occurrence of RTO time out, which may indicate that fast retransmission does not fix the issue. CAUTION if (value > 0).
Socket SCTP Congestion L3 — The total number of SCTP Congestion L3 packets. Indicates sending a new chunk is blocked due to CWND/RWND control, started buffering chunks in sending buffer for new chunks. WARNING if (value > 0).
Socket SCTP Congestion L4 — The total number of SCTP Congestion L4 packets. Indicates chunk drops locally due to either sending buffer exhausted or receiving buffer exhausted. ERROR if (value > 0).
Socket Retransmission Rx Count — The number Rx Retransmission sent by the socket. CAUTION if (value > 0).
Socket Retransmission Rx Bytes — The total number of bytes retransmitted by the socket. CAUTION if (value > 0).
Socket Retransmission Tx Count — The number Tx Retransmission sent by the socket. CAUTION if (value > 0).
Socket Retransmission Tx Bytes — The total number of bytes retransmitted by the socket. CAUTION if (value > 0).
The following measurements record the additional packet buffering performed during Diameter testing.
Retransmission Max Queued — The number of outgoing messages that were queued for retransmission attempts. When a message is sent, a copy is placed in the Retransmission Queue while waiting for a response. When a response is received, the queue is searched by sequence number and the message is removed.
Retransmission Overflowed — The number of times an attempt was made to add an outgoing message to the Retransmission Queue when the queue was full.
Retransmission Sequence Not Found — The number of times an attempt was made to remove a message from the Retransmission Queue but the sequence number was not found.
Retransmission Sequence Not Removed — The number of messages that were not removed from the Retransmission Queue.
Overflow Max Queued — The maximum number of outgoing messages that were queued to be sent. If the TCP connection with the Diameter peer is closed, new messages to be sent to the peer are held in the Overflow Queue until they can be sent.
Overflow Overflowed — The number of times an attempt was made to add a new message to the Overflow Queue when the queue was full. The queue can hold a maximum of 200 messages.
Overflow Message Re-queued — The number of times a message had to be placed back into the Overflow Queue because the TCP connection closed before the message could be sent.
These are the meanings of the MPTCP counters. Note that these descriptions of the counters are not in the same order as they appear on the measurements tab.
Socket MPTCP Mainflow Successes — number of MPTCP Mainflow sockets successfully established.
Socket MPTCP Mainflow Failures — number of MPTCP Mainflow sockets that failed to be established.
Socket MPTCP Subflow Successes — number of MPTCP Subflow sockets successfully established.
Socket MPTCP Subflow Failures — number of MPTCP Subflow sockets that failed to be established.
Socket MPTCP Capables Reset — number of TCP Resets received in response to an MPTCP Capable SYN.
Socket MPTCP Sockets Reverted to TCP — number MPTCP Mainflow sockets that reverted to regular TCP operation due to some type of failure – usually, but not always, indicating the other side of the connection does not support MPTCP.
Socket MPTCP Capables Not Received — number of times we expected an MPTCP Capable option to be included in a message but the option was not included. This could be an indication the other side of the connection does not support MPTCP.
Socket MPTCP Mismatched Keys — number of times the keys received in the MPTCP SYN ACK did not match expected values.
Socket MPTCP Joins Reset — number of TCP Resets received in response to an MPTCP Join.
Socket MPTCP Incorrect HMAC Received — number of times the HMAC value received (in response to a Join) didn’t match the expected value.
Socket MPTCP Joins Not Received — number of times we expected an MPTCP Join option to be included in a message but the option was not included. We would only send a Join if we knew the other side supported MPTCP, therefor this error is an indication of something other than the far end not supporting MPTCP.
Socket MPTCP Joins Received Before Mainflow Established — number of times a JOIN is received before the MPTCP Mainflow socket has been established.
Socket MPTCP Poorly Formed Packets — number of times an MPTCP option was received that is poorly formatted (and could not be properly decoded).
Socket MPTCP Unknown Option Packets — number of times a properly formatted MPTCP option included and unknown suboption type.
Socket MPTCP Unexpected Capables Received — number of times an MPTCP socket received an MPTCP Capable option that it wasn’t expecting.
Socket MPTCP Unexpected Joins Received — number of times an MPTCP socket received an MPTCP Join option that it wasn’t expecting.
Socket MPTCP DSN Not Received — number of times a received MPTCP Data Sequence Signal did not include a Data Sequence number that was expected.
Socket MPTCP Reordered Packets — number of times data is received out of order at the MPTCP layer. This is not an error and can be somewhat expected. Out of order packets are queued and processed when the expected data eventually arrives.
For the Client side test case the measurements for both the MPTCP Mainflow and MPTCP Subflow are combined into the same Sess_x tab. For example if there are 5 subscribers there are 5 Sess_x tabs and each tab has both main and subflow counters included.