IMS CSCF Metrics Reference
This document provides a comprehensive reference for all metrics exported by the P-CSCF, I-CSCF, and S-CSCF components.
Accessing Metrics
All CSCF components expose Prometheus metrics on port 9090:
http://<host>:9090/metrics
Each CSCF host (P-CSCF, I-CSCF, S-CSCF) exports its own metrics. Configure your Prometheus server to scrape all hosts for complete monitoring coverage.
Example Prometheus Configuration:
scrape_configs:
- job_name: 'cscf_pcscf'
static_configs:
- targets: ['pcscf1.example.com:9090', 'pcscf2.example.com:9090']
- job_name: 'cscf_icscf'
static_configs:
- targets: ['icscf1.example.com:9090']
- job_name: 'cscf_scscf'
static_configs:
- targets: ['scscf1.example.com:9090', 'scscf2.example.com:9090']
For operational guidance on monitoring and alerting, see:
Monitoring Through Control Panel
The OmniCall CSCF Control Panel provides real-time visibility into the operational state that generates these metrics. While metrics are exported via Prometheus for historical analysis and alerting, the control panel shows the current state of registrations, dialogs, and Diameter peers.
S-CSCF Management
View active registrations and user location data:
The registration count visible in the UI corresponds to metrics like ims_usrloc_scscf_active_impus and ims_usrloc_scscf_active_contacts.
Diameter Peer Monitoring
Monitor Diameter peer status and queue lengths:
The queue length shown here corresponds to the cdp_queuelength metric. Peer state "I_Open" indicates healthy connections.
Each peer shows supported Diameter applications. For example:
- 16777216:10415 (Cx/Dx) - Used by I-CSCF and S-CSCF for HSS communication (UAR, LIR, MAR, SAR)
- 16777236:10415 (Rx) - Used by P-CSCF for PCRF QoS policy
- 4 (Ro) - Used by S-CSCF for online charging
These correspond to metrics like ims_icscf_uar_*, ims_icscf_lir_*, ims_auth_mar_*, ims_registrar_scscf_sar_*, and ims_qos_*.
P-CSCF Metrics
CDP (Diameter) Metrics
| Metric Name | Meaning |
|---|
cdp_average_response_time | Average response time for Diameter requests in milliseconds (calculated as replies_response_time / replies_received) |
cdp_queuelength | Current length of the Diameter worker queue tasks |
cdp_replies_received | Total number of Diameter replies received |
cdp_replies_response_time | Total time spent waiting for Diameter replies in milliseconds |
cdp_timeout | Number of timeout events on Diameter requests |
Core SIP Statistics
Request Counters
| Metric Name | Meaning |
|---|
core_rcv_requests | Total number of SIP requests received |
core_rcv_requests_ack | Number of ACK requests received |
core_rcv_requests_bye | Number of BYE requests received |
core_rcv_requests_cancel | Number of CANCEL requests received |
core_rcv_requests_info | Number of INFO requests received |
core_rcv_requests_invite | Number of INVITE requests received |
core_rcv_requests_message | Number of MESSAGE requests received |
core_rcv_requests_notify | Number of NOTIFY requests received |
core_rcv_requests_options | Number of OPTIONS requests received |
core_rcv_requests_prack | Number of PRACK requests received |
core_rcv_requests_publish | Number of PUBLISH requests received |
core_rcv_requests_refer | Number of REFER requests received |
core_rcv_requests_register | Number of REGISTER requests received |
core_rcv_requests_subscribe | Number of SUBSCRIBE requests received |
core_rcv_requests_update | Number of UPDATE requests received |
Reply Counters (General)
| Metric Name | Meaning |
|---|
core_rcv_replies | Total number of SIP replies received |
core_rcv_replies_18x | Number of 180/181/183/186/187/189 provisional responses received |
core_rcv_replies_1xx | Number of 1xx (provisional) responses received |
core_rcv_replies_2xx | Number of 2xx (success) responses received |
core_rcv_replies_3xx | Number of 3xx (redirection) responses received |
core_rcv_replies_4xx | Number of 4xx (client error) responses received |
core_rcv_replies_5xx | Number of 5xx (server error) responses received |
core_rcv_replies_6xx | Number of 6xx (global failure) responses received |
Reply Counters by Method (1xx)
| Metric Name | Meaning |
|---|
core_rcv_replies_1xx_bye | Number of 1xx responses to BYE requests |
core_rcv_replies_1xx_cancel | Number of 1xx responses to CANCEL requests |
core_rcv_replies_1xx_invite | Number of 1xx responses to INVITE requests |
core_rcv_replies_1xx_message | Number of 1xx responses to MESSAGE requests |
core_rcv_replies_1xx_prack | Number of 1xx responses to PRACK requests |
core_rcv_replies_1xx_refer | Number of 1xx responses to REFER requests |
core_rcv_replies_1xx_reg | Number of 1xx responses to REGISTER requests |
core_rcv_replies_1xx_update | Number of 1xx responses to UPDATE requests |
Reply Counters by Method (2xx)
| Metric Name | Meaning |
|---|
core_rcv_replies_2xx_bye | Number of 2xx (success) responses to BYE requests |
core_rcv_replies_2xx_cancel | Number of 2xx (success) responses to CANCEL requests |
core_rcv_replies_2xx_invite | Number of 2xx (success) responses to INVITE requests |
core_rcv_replies_2xx_message | Number of 2xx (success) responses to MESSAGE requests |
core_rcv_replies_2xx_prack | Number of 2xx (success) responses to PRACK requests |
core_rcv_replies_2xx_refer | Number of 2xx (success) responses to REFER requests |
core_rcv_replies_2xx_reg | Number of 2xx (success) responses to REGISTER requests |
core_rcv_replies_2xx_update | Number of 2xx (success) responses to UPDATE requests |
Reply Counters by Method (3xx)
| Metric Name | Meaning |
|---|
core_rcv_replies_3xx_bye | Number of 3xx (redirection) responses to BYE requests |
core_rcv_replies_3xx_cancel | Number of 3xx (redirection) responses to CANCEL requests |
core_rcv_replies_3xx_invite | Number of 3xx (redirection) responses to INVITE requests |
core_rcv_replies_3xx_message | Number of 3xx (redirection) responses to MESSAGE requests |
core_rcv_replies_3xx_prack | Number of 3xx (redirection) responses to PRACK requests |
core_rcv_replies_3xx_refer | Number of 3xx (redirection) responses to REFER requests |
core_rcv_replies_3xx_reg | Number of 3xx (redirection) responses to REGISTER requests |
core_rcv_replies_3xx_update | Number of 3xx (redirection) responses to UPDATE requests |
Reply Counters by Method (4xx)
| Metric Name | Meaning |
|---|
core_rcv_replies_4xx_bye | Number of 4xx (client error) responses to BYE requests |
core_rcv_replies_4xx_cancel | Number of 4xx (client error) responses to CANCEL requests |
core_rcv_replies_4xx_invite | Number of 4xx (client error) responses to INVITE requests |
core_rcv_replies_4xx_message | Number of 4xx (client error) responses to MESSAGE requests |
core_rcv_replies_4xx_prack | Number of 4xx (client error) responses to PRACK requests |
core_rcv_replies_4xx_refer | Number of 4xx (client error) responses to REFER requests |
core_rcv_replies_4xx_reg | Number of 4xx (client error) responses to REGISTER requests |
core_rcv_replies_4xx_update | Number of 4xx (client error) responses to UPDATE requests |
Reply Counters by Method (5xx)
| Metric Name | Meaning |
|---|
core_rcv_replies_5xx_bye | Number of 5xx (server error) responses to BYE requests |
core_rcv_replies_5xx_cancel | Number of 5xx (server error) responses to CANCEL requests |
core_rcv_replies_5xx_invite | Number of 5xx (server error) responses to INVITE requests |
core_rcv_replies_5xx_message | Number of 5xx (server error) responses to MESSAGE requests |
core_rcv_replies_5xx_prack | Number of 5xx (server error) responses to PRACK requests |
core_rcv_replies_5xx_refer | Number of 5xx (server error) responses to REFER requests |
core_rcv_replies_5xx_reg | Number of 5xx (server error) responses to REGISTER requests |
core_rcv_replies_5xx_update | Number of 5xx (server error) responses to UPDATE requests |
Reply Counters by Method (6xx)
| Metric Name | Meaning |
|---|
core_rcv_replies_6xx_bye | Number of 6xx (global failure) responses to BYE requests |
core_rcv_replies_6xx_cancel | Number of 6xx (global failure) responses to CANCEL requests |
core_rcv_replies_6xx_invite | Number of 6xx (global failure) responses to INVITE requests |
core_rcv_replies_6xx_message | Number of 6xx (global failure) responses to MESSAGE requests |
core_rcv_replies_6xx_prack | Number of 6xx (global failure) responses to PRACK requests |
core_rcv_replies_6xx_refer | Number of 6xx (global failure) responses to REFER requests |
core_rcv_replies_6xx_reg | Number of 6xx (global failure) responses to REGISTER requests |
core_rcv_replies_6xx_update | Number of 6xx (global failure) responses to UPDATE requests |
Specific Status Code Counters
| Metric Name | Meaning |
|---|
core_rcv_replies_400 | Number of 400 Bad Request responses received |
core_rcv_replies_401 | Number of 401 Unauthorized responses received |
core_rcv_replies_402 | Number of 402 Payment Required responses received |
core_rcv_replies_403 | Number of 403 Forbidden responses received |
core_rcv_replies_404 | Number of 404 Not Found responses received |
core_rcv_replies_405 | Number of 405 Method Not Allowed responses received |
core_rcv_replies_406 | Number of 406 Not Acceptable responses received |
core_rcv_replies_407 | Number of 407 Proxy Authentication Required responses received |
core_rcv_replies_408 | Number of 408 Request Timeout responses received |
core_rcv_replies_409 | Number of 409 Conflict responses received |
core_rcv_replies_410 | Number of 410 Gone responses received |
core_rcv_replies_411 | Number of 411 Length Required responses received |
core_rcv_replies_413 | Number of 413 Request Entity Too Large responses received |
core_rcv_replies_414 | Number of 414 Request-URI Too Long responses received |
core_rcv_replies_415 | Number of 415 Unsupported Media Type responses received |
core_rcv_replies_420 | Number of 420 Bad Extension responses received |
core_rcv_replies_480 | Number of 480 Temporarily Unavailable responses received |
core_rcv_replies_481 | Number of 481 Call/Transaction Does Not Exist responses received |
core_rcv_replies_482 | Number of 482 Loop Detected responses received |
core_rcv_replies_483 | Number of 483 Too Many Hops responses received |
core_rcv_replies_484 | Number of 484 Address Incomplete responses received |
core_rcv_replies_485 | Number of 485 Ambiguous responses received |
core_rcv_replies_486 | Number of 486 Busy Here responses received |
core_rcv_replies_487 | Number of 487 Request Terminated responses received |
core_rcv_replies_488 | Number of 488 Not Acceptable Here responses received |
core_rcv_replies_489 | Number of 489 Bad Event responses received |
core_rcv_replies_491 | Number of 491 Request Pending responses received |
core_rcv_replies_493 | Number of 493 Undecipherable responses received |
Forwarding and Error Statistics
| Metric Name | Meaning |
|---|
core_fwd_replies | Number of SIP replies forwarded |
core_fwd_requests | Number of SIP requests forwarded |
core_drop_replies | Number of SIP replies dropped |
core_drop_requests | Number of SIP requests dropped |
core_err_replies | Number of error replies |
core_err_requests | Number of error requests |
core_bad_URIs_rcvd | Number of messages with malformed URIs received |
core_bad_msg_hdr | Number of messages with bad/malformed headers |
core_unsupported_methods | Number of requests with unsupported SIP methods |
Dialog Tracking
| Metric Name | Meaning |
|---|
dialog_ng_active | Number of currently active (answered/confirmed) dialogs |
dialog_ng_early | Number of early dialogs (ringing/provisional state) |
dialog_ng_expired | Number of dialogs that have expired or been forcibly terminated |
dialog_ng_processed | Total number of dialogs processed since startup |
DNS Statistics
| Metric Name | Meaning |
|---|
dns_failed_dns_request | Number of failed DNS queries |
dns_slow_dns_request | Number of slow DNS queries (exceeding threshold) |
IMS IPSec P-CSCF
| Metric Name | Meaning |
|---|
ims_ipsec_pcscf_spi_free | Number of free SPI (Security Parameter Index) values available for allocation |
ims_ipsec_pcscf_spi_total | Total SPI capacity configured for the system |
ims_ipsec_pcscf_spi_used | Number of currently allocated/used SPI values |
ims_ipsec_pcscf_spi_utilization_pct | Percentage of SPI pool utilization |
ims_ipsec_pcscf_worker_cache_size | Size of the worker process IPSec cache |
IMS QoS (Rx Interface)
Registration AAR Metrics
| Metric Name | Meaning |
|---|
ims_qos_active_registration_rx_sessions | Number of currently active registration Rx sessions |
ims_qos_registration_aars | Total number of registration AAR (Authorization-Authentication Request) messages sent |
ims_qos_successful_registration_aars | Number of successful registration AAR transactions |
ims_qos_failed_registration_aars | Number of failed registration AAR transactions |
ims_qos_registration_aar_avg_response_time | Average response time for registration AAR messages in milliseconds |
ims_qos_registration_aar_response_time | Total response time for all registration AAR messages in milliseconds |
ims_qos_registration_aar_replies_received | Total number of registration AAR replies received |
ims_qos_registration_aar_timeouts | Number of registration AAR request timeouts |
| Metric Name | Meaning |
|---|
ims_qos_active_media_rx_sessions | Number of currently active media Rx sessions |
ims_qos_media_rx_sessions | Total number of media Rx sessions created |
ims_qos_media_aars | Total number of media AAR messages sent |
ims_qos_successful_media_aars | Number of successful media AAR transactions |
ims_qos_failed_media_aars | Number of failed media AAR transactions |
ims_qos_media_aar_avg_response_time | Average response time for media AAR messages in milliseconds |
ims_qos_media_aar_response_time | Total response time for all media AAR messages in milliseconds |
ims_qos_media_aar_replies_received | Total number of media AAR replies received |
ims_qos_media_aar_timeouts | Number of media AAR request timeouts |
ASR Metrics
| Metric Name | Meaning |
|---|
ims_qos_asrs | Total number of ASR (Abort-Session-Request) messages received from PCRF |
IMS USRLOC P-CSCF
| Metric Name | Meaning |
|---|
ims_usrloc_pcscf_expired_contacts | Number of expired contact bindings |
ims_usrloc_pcscf_registered_contacts | Number of currently registered contact bindings |
ims_usrloc_pcscf_registered_impus | Number of currently registered IMPUs (IMS Public User Identities) |
MySQL Database
| Metric Name | Meaning |
|---|
mysql_driver_errors | Number of MySQL driver/connection errors |
Pike Module (IP Blocking)
| Metric Name | Meaning |
|---|
pike_blocked_ips | Number of currently blocked IP addresses (flood detection) |
Registrar Module
| Metric Name | Meaning |
|---|
registrar_accepted_regs | Number of accepted REGISTER requests (legacy registrar module) |
registrar_rejected_regs | Number of rejected REGISTER requests (legacy registrar module) |
registrar_default_expire | Default expiration time for registrations in seconds |
registrar_default_expires_range | Default expires range setting |
registrar_expires_range | Configured expires range |
registrar_max_contacts | Maximum number of contacts allowed per AOR |
registrar_max_expires | Maximum expiration time allowed in seconds |
Script Statistics
| Metric Name | Meaning |
|---|
script_register_failed | Number of registration attempts that failed in routing script logic |
script_register_success | Number of successful registrations processed by routing script |
script_register_time | Total time spent processing registrations in routing script (milliseconds) |
SCTP Transport
| Metric Name | Meaning |
|---|
sctp_assoc_shutdown | Number of locally initiated SCTP association shutdowns |
sctp_comm_lost | Number of SCTP associations lost due to communication failure |
sctp_connect_failed | Number of failed outgoing SCTP association attempts |
sctp_current_opened_connections | Number of currently opened SCTP associations |
sctp_current_tracked_connections | Number of currently tracked SCTP associations |
sctp_established | Total number of SCTP associations established |
sctp_local_reject | Number of incoming SCTP associations rejected locally |
sctp_remote_shutdown | Number of peer-initiated SCTP association shutdowns |
sctp_send_failed | Number of SCTP send operations that failed |
sctp_send_force_retry | Number of forced retries on failed SCTP sends |
sctp_sendq_full | Number of send attempts that failed due to full send queue |
Shared Memory
| Metric Name | Meaning |
|---|
shmem_fragments | Number of fragments in shared memory pool (indicates fragmentation) |
shmem_free_size | Amount of free shared memory in bytes |
shmem_max_used_size | Maximum shared memory used since startup in bytes |
shmem_real_used_size | Real used shared memory including allocator overhead in bytes |
shmem_total_size | Total shared memory pool size in bytes |
shmem_used_size | Currently used shared memory (user data only) in bytes |
SL (Stateless) Module
Stateless Reply Counters by Class
| Metric Name | Meaning |
|---|
sl_1xx_replies | Number of 1xx stateless replies sent |
sl_2xx_replies | Number of 2xx stateless replies sent |
sl_3xx_replies | Number of 3xx stateless replies sent |
sl_4xx_replies | Number of 4xx stateless replies sent |
sl_5xx_replies | Number of 5xx stateless replies sent |
sl_6xx_replies | Number of 6xx stateless replies sent |
sl_xxx_replies | Number of other stateless replies sent |
Specific Stateless Reply Counters
| Metric Name | Meaning |
|---|
sl_200_replies | Number of 200 OK stateless replies sent |
sl_202_replies | Number of 202 Accepted stateless replies sent |
sl_300_replies | Number of 300 Multiple Choices stateless replies sent |
sl_301_replies | Number of 301 Moved Permanently stateless replies sent |
sl_302_replies | Number of 302 Moved Temporarily stateless replies sent |
sl_400_replies | Number of 400 Bad Request stateless replies sent |
sl_401_replies | Number of 401 Unauthorized stateless replies sent |
sl_403_replies | Number of 403 Forbidden stateless replies sent |
sl_404_replies | Number of 404 Not Found stateless replies sent |
sl_407_replies | Number of 407 Proxy Authentication Required stateless replies sent |
sl_408_replies | Number of 408 Request Timeout stateless replies sent |
sl_483_replies | Number of 483 Too Many Hops stateless replies sent |
sl_500_replies | Number of 500 Server Internal Error stateless replies sent |
Stateless General Statistics
| Metric Name | Meaning |
|---|
sl_sent_replies | Total number of stateless replies sent |
sl_sent_err_replies | Number of stateless error replies sent |
sl_received_ACKs | Number of ACK messages received for stateless transactions |
sl_failures | Number of stateless reply send failures |
TCP Transport
| Metric Name | Meaning |
|---|
tcp_con_reset | Number of TCP connections reset (RST received on established connection) |
tcp_con_timeout | Number of TCP connections closed due to idle timeout |
tcp_connect_failed | Number of failed outgoing TCP connection attempts |
tcp_connect_success | Number of successful outgoing TCP connections |
tcp_current_opened_connections | Number of currently opened TCP connections |
tcp_current_write_queue_size | Current total size of TCP write queues across all connections |
tcp_established | Total number of TCP connections established (both incoming and outgoing) |
tcp_local_reject | Number of incoming TCP connections rejected locally |
tcp_passive_open | Number of accepted incoming TCP connections |
tcp_send_timeout | Number of TCP send operations that timed out (async mode) |
tcp_sendq_full | Number of send attempts that failed because the send queue was full |
TM/TMX (Transaction) Module
Transaction Type Counters
| Metric Name | Meaning |
|---|
tmx_UAC_transactions | Number of UAC (client) transactions created |
tmx_UAS_transactions | Number of UAS (server) transactions created |
tmx_active_transactions | Number of currently active transactions |
tmx_inuse_transactions | Number of transactions currently in use |
Transaction Completion by Status
| Metric Name | Meaning |
|---|
tmx_2xx_transactions | Number of transactions completed with 2xx response |
tmx_3xx_transactions | Number of transactions completed with 3xx response |
tmx_4xx_transactions | Number of transactions completed with 4xx response |
tmx_5xx_transactions | Number of transactions completed with 5xx response |
tmx_6xx_transactions | Number of transactions completed with 6xx response |
Transaction Reply Statistics
| Metric Name | Meaning |
|---|
tmx_rpl_absorbed | Number of replies absorbed by the transaction layer (duplicates) |
tmx_rpl_generated | Number of replies generated locally by the transaction module |
tmx_rpl_received | Number of replies received for transactions |
tmx_rpl_relayed | Number of replies relayed by the transaction module |
tmx_rpl_sent | Number of replies sent by the transaction module |
USRLOC (User Location)
| Metric Name | Meaning |
|---|
usrloc_location_contacts | Number of contacts in the 'location' domain (standard usrloc module) |
usrloc_location_expires | Number of expired contacts in the 'location' domain |
usrloc_registered_users | Number of registered users/AORs (Address of Records) |
I-CSCF Metrics
The I-CSCF shares most core SIP statistics with the P-CSCF (see P-CSCF Core SIP Statistics section above). The following metrics are specific to I-CSCF functionality.
I-CSCF Operational Context
The I-CSCF maintains a list of available S-CSCF instances for load balancing:
The I-CSCF queries the HSS to select appropriate S-CSCF instances for new registrations. The success of these operations is tracked in the UAR and LIR metrics below.
IMS I-CSCF (Cx Interface - HSS Communication)
The I-CSCF uses the Diameter Cx interface to communicate with the HSS (Home Subscriber Server) for user location and authorization queries.
UAR (User-Authorization-Request) Metrics
| Metric Name | Meaning |
|---|
ims_icscf_uar_avg_response_time | Average response time for UAR messages in milliseconds (calculated as uar_replies_response_time / uar_replies_received) |
ims_icscf_uar_replies_received | Total number of UAA (User-Authorization-Answer) replies received from HSS |
ims_icscf_uar_replies_response_time | Total response time for all UAR messages in milliseconds |
ims_icscf_uar_timeouts | Number of UAR request timeouts |
LIR (Location-Info-Request) Metrics
| Metric Name | Meaning |
|---|
ims_icscf_lir_avg_response_time | Average response time for LIR messages in milliseconds (calculated as lir_replies_response_time / lir_replies_received) |
ims_icscf_lir_replies_received | Total number of LIA (Location-Info-Answer) replies received from HSS |
ims_icscf_lir_replies_response_time | Total response time for all LIR messages in milliseconds |
ims_icscf_lir_timeouts | Number of LIR request timeouts |
Common Metrics
The I-CSCF also exports the following common metrics (documented in the P-CSCF section above):
- CDP (Diameter) Metrics - Diameter protocol statistics
- Core SIP Statistics - Request/reply counters by method and status code
- DNS Statistics - DNS query metrics
- MySQL Database - Database connection errors
- Pike Module - IP blocking statistics
- Shared Memory - Memory usage statistics
- SL (Stateless) Module - Stateless reply counters
- TCP Transport - TCP connection statistics
- TM/TMX (Transaction) Module - Transaction state tracking
S-CSCF Metrics
The S-CSCF shares most core SIP statistics with the P-CSCF and I-CSCF (see P-CSCF Core SIP Statistics section above). The following metrics are specific to S-CSCF functionality.
S-CSCF Operational Context
The S-CSCF provides detailed user location information and IFC (Initial Filter Criteria) management:
User location lookup shows registered IMPUs with contact bindings and service profiles. The number of active contacts and IMPUs is tracked by ims_usrloc_scscf_active_contacts and ims_usrloc_scscf_active_impus metrics.
IFC (Initial Filter Criteria) determines which Application Servers process SIP sessions. The control panel allows dumping and testing IFC rules. IFC evaluation performance can impact call setup times tracked in transaction metrics (tmx_*).
IMS ISC (IMS Service Control)
The IMS ISC module handles Initial Filter Criteria (iFC) evaluation to determine which Application Servers should process SIP sessions. These metrics track the performance and effectiveness of iFC matching operations.
| Metric Name | Meaning |
|---|
ims_isc_ifc_match_attempts | Total number of iFC matching attempts performed |
ims_isc_ifc_match_time_total | Cumulative time spent performing iFC matching operations in milliseconds |
ims_isc_ifc_nomatch_count | Number of iFC matching attempts where no trigger criteria matched |
Performance Monitoring: Calculate average iFC match time as ifc_match_time_total / ifc_match_attempts. High average times may indicate complex filter criteria or performance bottlenecks in Application Server selection. A high ratio of ifc_nomatch_count to ifc_match_attempts may indicate misconfigured trigger points or unexpected traffic patterns.
IMS Authentication (Cx Interface - MAR)
The S-CSCF uses Diameter Cx interface to authenticate users with the HSS via MAR (Multimedia-Auth-Request).
| Metric Name | Meaning |
|---|
ims_auth_mar_avg_response_time | Average response time for MAR messages in milliseconds (calculated as mar_replies_response_time / mar_replies_received) |
ims_auth_mar_replies_received | Total number of MAA (Multimedia-Auth-Answer) replies received from HSS |
ims_auth_mar_replies_response_time | Total response time for all MAR messages in milliseconds |
ims_auth_mar_timeouts | Number of MAR request timeouts |
IMS Registrar S-CSCF
Registration Statistics
| Metric Name | Meaning |
|---|
ims_registrar_scscf_accepted_regs | Number of successfully accepted REGISTER requests |
ims_registrar_scscf_rejected_regs | Number of rejected REGISTER requests |
ims_registrar_scscf_default_expire | Default expiration time for registrations in seconds |
ims_registrar_scscf_default_expires_range | Default expires range configuration |
ims_registrar_scscf_max_contacts | Maximum number of contacts allowed per registration |
ims_registrar_scscf_max_expires | Maximum expiration time allowed in seconds |
ims_registrar_scscf_notifies_in_q | Number of pending NOTIFY messages in the queue |
SAR (Server-Assignment-Request) Metrics
| Metric Name | Meaning |
|---|
ims_registrar_scscf_sar_avg_response_time | Average response time for SAR messages in milliseconds (calculated as sar_replies_response_time / sar_replies_received) |
ims_registrar_scscf_sar_replies_received | Total number of SAA (Server-Assignment-Answer) replies received from HSS |
ims_registrar_scscf_sar_replies_response_time | Total response time for all SAR messages in milliseconds |
ims_registrar_scscf_sar_timeouts | Number of SAR request timeouts |
IMS USRLOC S-CSCF
| Metric Name | Meaning |
|---|
ims_usrloc_scscf_active_contacts | Number of currently active registered contact bindings |
ims_usrloc_scscf_active_impus | Number of currently active registered IMPUs (IMS Public User Identities) |
ims_usrloc_scscf_active_subscriptions | Number of currently active subscriptions |
ims_usrloc_scscf_contact_collisions | Number of hash collisions in the contact hash table |
ims_usrloc_scscf_impu_collisions | Number of hash collisions in the IMPU hash table |
ims_usrloc_scscf_subscription_collisions | Number of hash collisions in the subscription hash table |
Dialog Tracking
The S-CSCF tracks dialog state for active calls:
| Metric Name | Meaning |
|---|
dialog_ng_active | Number of currently active (answered/confirmed) dialogs |
dialog_ng_early | Number of early dialogs (ringing/provisional state) |
dialog_ng_expired | Number of dialogs that have expired or been forcibly terminated |
dialog_ng_processed | Total number of dialogs processed since startup |
Common Metrics
The S-CSCF also exports the following common metrics (documented in the P-CSCF section above):
- CDP (Diameter) Metrics - Diameter protocol statistics
- Core SIP Statistics - Request/reply counters by method and status code (note: S-CSCF typically has higher fwd_requests and fwd_replies as it routes between endpoints)
- DNS Statistics - DNS query metrics
- MySQL Database - Database connection errors
- Pike Module - IP blocking statistics
- Shared Memory - Memory usage statistics
- SL (Stateless) Module - Stateless reply counters
- TCP Transport - TCP connection statistics
- TM/TMX (Transaction) Module - Transaction state tracking (note: S-CSCF typically has both UAC and UAS transactions as it acts as both client and server)