The show processes top command displays realtime updates of per-process CPU utilization. To quit, press "q".

ORACLE> show processes top
top - 13:57:22 up 23:48,  0 users,  load average: 0.00, 0.01, 0.05
Tasks: 117 total,   2 running, 115 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   2966240k total,   398016k used,  2568224k free,    66536k buffers
Swap:        0k total,        0k used,        0k free,   116032k cached
  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
    1 root      20   0  3724 1100  936 S    0  0.0   0:30.13 init
    2 root      20   0     0    0    0 S    0  0.0   0:00.00 kthreadd
    3 root      20   0     0    0    0 S    0  0.0   0:04.49 ksoftirqd/0
    6 root      RT   0     0    0    0 S    0  0.0   0:00.00 migration/0
    7 root      RT   0     0    0    0 S    0  0.0   0:00.33 watchdog/0
    8 root      RT   0     0    0    0 S    0  0.0   0:00.00 migration/1
    9 root      20   0     0    0    0 S    0  0.0   0:00.00 kworker/1:0
   10 root      20   0     0    0    0 S    0  0.0   0:00.08 ksoftirqd/1
   11 root      20   0     0    0    0 R    0  0.0   0:02.16 kworker/0:1
   12 root      RT   0     0    0    0 S    0  0.0   0:00.17 watchdog/1
   13 root       0 -20     0    0    0 S    0  0.0   0:00.00 khelper
  418 root      20   0     0    0    0 S    0  0.0   0:00.13 sync_supers
  420 root      20   0     0    0    0 S    0  0.0   0:00.00 bdi-default
  421 root       0 -20     0    0    0 S    0  0.0   0:00.00 kblockd
  423 root      20   0     0    0    0 S    0  0.0  11:31.98 kworker/1:1
  559 root       0 -20     0    0    0 S    0  0.0   0:00.00 ata_sff
  570 root      20   0     0    0    0 S    0  0.0   0:00.00 khubd

Check the amount of storage space is available on the flash file system on the following devices by using the check-space-remaining command:

• /boot
• /code
• /crash
• /opt
• the data-disk, system-disks or a combination

For example:

ORACLE# check-space-remaining boot
boot: 20127744/29760512 bytes (67%) remaining

This section explains how and when the Oracle Communications Session Border Controller performs SIP message throttling to limit CPU utilization. This configuration also affects IDS management information.

The Oracle Communications Session Border Controller limits CPU utilization by SIP requests using two utilization percentage points. When CPU utilization reaches the first point, the system begins to reject SIP requests. When it reaches the second point, the system rejects all SIP requests. By default, these values are 90% and 99%. The user can change these values using a sip-config option called load-limit.

The load-limit option accepts two parameters, from which it determines these levels, including:

• Minimum CPU Utilization - The CPU utilization percentage at which the system begins to throttle back on the SIP requests it processes.
• CPU Limit for Headroom Calculation - A variable the system uses to compute maximum CPU utilization, at which it stops accepting SIP requests.

Syntax for this option is:

 load-limit= < Minimum CPU Utilization  > [-< CPU Limit for Headroom Calculation >]

User settings include:

• Minimum CPU Utilization - The range is 15% to 100%, and the default is 90%.
• (Optional) CPU Limit for Headroom Calculation - The range is 15 to 100, and the default is 100.

The calculation the system uses to determine the maximum CPU percent utilization is shown below, with X representing the Minimum CPU Utilization, and Y representing the CPU Limit for Headroom Calculation.

 X + ((Y - X) * X/Y)%

The example setting below sets the throttling threshold to 60% and the maximum utilization to 75%.

 load-limit= 60-80

The calculation the system uses is 60 + (80 - 60) * 60/80 = 75

The system progressively rejects requests as CPU utilization increases. When CPU utilization is between X% and the maximum, the system accepts some new SIP requests, depending on CPU utilization and utilization configuration. The system calculates this acceptance rate using the formula below.

100 - ((Current CPU Util - X) * 100 / ((Y - X) * X/Y))

When CPU utilization reaches its maximum, it drops all new SIP requests. The system resumes accepting requests when CPU utilization falls below its maximum, and stops throttling when it falls below the Minimum CPU Utilization.

While rejecting a SIP request, the system returns a 503 service unavailable message, along with a Retry-After header. The user can configure the reject-interval using the sip-config's reject-interval=X option. The default value is 1 second.

The actual value of reject interval header embedded in the 503 message is:

RetryAfter = (100 - Acceptance Rate) /10 * rejectInterval

If this value is smaller than the configured reject-interval, the system overwrites it with the configured reject-interval value.

Note the table below, which displays some valid and invalid configuration entries.

You can configure the SBC to use overall system CPU thresholds in addition SIP thread specific CPU thresholds as criteria for managing CPU utilization. This feature is supported on both SWDP and HWDP platforms. For SWDP platforms, the SBC calculates overall CPU as the cumulative utilization of all cores. For HWDP platforms, the SBC calculates overall CPU as the cumulative utilization of all signaling cores. This feature is applicable only for dialog creating SIP requests, including INVITE and SUBSCRIBE, and is not applicable for responses. The action the system takes for this feature is to drop random, then all new SIP calls. This feature, however, never causes the system to drop priority calls.

Without this feature, the SBC can admit/reject new SIP calls on a per-sipd thread basis rather than considering overall CPU utilization. You configure the load-limit option in the sip-config to perform this function. But it is possible for the overall system CPU to be overloaded even though the sipd thread CPU is below its threshold limit. With this new feature, you can extend your CPU monitoring configuration by setting the syscpu-load-limit option in the system-config. This evaluates CPU resources available system wide, rather than those consumed by a specific thread.

Details on load-limit configuration, operational calculations and behaviors are the same with the syscpu-load-limit. The former measures and acts on CPU utilization by individual SIPD threads; the latter is based on overall CPU utilization. Both the load-limit and syscpu-load-limit options begin to reject random, new calls (INVITE/SUBSCRIBE) when they reach their minimum thresholds, and reject all new calls when they reach their maximum thresholds. When a syscpu-load-limit threshold is exceeded, the system stabilizes by rejecting calls, regardless of the sipd thread status.

These rejections are the only actions taken to reduce CPU load. The system rejects new calls (INVITE/SUBSCRIBE) from SIPD with a 503, thereby preventing retransmissions from the UAS.

This enhancement is disabled by default. Option syntax is shown below.

ORACLE(system-config)# options +syscpu-load-limit=[X]-[Y].

• X specifies the percent CPU utilization at which the system starts rejecting some SIP requests. The default is 90% and the valid range is 15 to 100.
• Y specifies the calculation variable the system uses to determine maximum percent CPU utilization, which is based on current system CPU headroom, and is optional. This setting determines the difference between system MinCPU utilization and MaxCPU utilization. The default is 100 and the valid range is 15 to 100.

  The SBC calculates system CPU headroom using the formula ((Y-X)*X/Y)%. This value becomes the percentage CPU above MinCPU, at which the system proceeds from rejecting random new calls to rejecting all new calls (INVITE/out of dialog SUBSCRIBE).

• If X is greater than the Y, the system sets Y to 100 and uses X as the operational value.

System behaviors when configured with the syscpu-load-limit option include:

• If current system CPU is less than MinCPU, it accepts all new requests.
• If the current SIPD threads reaches the minimum CPU threshold, the system begins to reject some random calls (throttling).
• While rejecting a SIP request, the system returns a 503 service unavailable message, along with a Retry-After header.
• If overall CPU utilization reaches the maximum CPU threshold (throttling threshold + CPU headroom), the system drops all new SIP requests.
• The system resumes accepting requests when CPU utilization falls below its maximum, and stops throttling when it falls below the Minimum CPU Utilization.

You can also configure the value the system sends for the Retry Header. When configuring syscpu-load-limit, you can configure the syscpu-reject-interval in the system-config. This value specifies the time in seconds the system inserts as the value of the Retry-After header.

The default value for the syscpu-reject-interval option is 1 second. If the calculated reject-interval value is smaller than the configured syscpu-reject-interval, the system overwrites it with the configured reject-interval value.

ORACLE(system-config)# options +syscpu-reject-interval=5

ORACLE# show platform cpu-load
Timestamp: 14:28:00 Tue 2024-05-28
Total load   :     1%
CPU 00 load  :     2%
CPU 01 load  :     1%
CPU 02 load  :     2%
CPU 03 load  :     1%

ORACLE# show processes overload
ATCPD:
Thread Name     Active     CPU Usage     CPU Overloaded
    atcpd01         No          0.0%                 No

MBCD:
Thread Name     Active     CPU Usage     CPU Overloaded
     mbcd01         No          0.0%                 No

SIPD:
Thread Name     Active     CPU Usage     CPU Overloaded
     sipd01         No          0.0%                 No
ORACLE#

ORACLE# show system-overload
10:51:47-80
Minimum CPU Load Limit (Configured) : 20
Maximum CPU Load Limit (Configured) : 30
Maximum CPU Load Limit (Calculated) : 26
System CPU Headroom (Calculated)    : 6
System:
Active     CPU Usage     CPU Overloaded   
Yes            1%                 No

Alarm ID 131342 
System CPU is at 92 percent, over minor/major/critical threshold of 85 percent 

1. Access the sip-config configuration element.

   ORACLE# configure terminal
   ORACLE(configure)# session-router
   ORACLE(session-router)# sip-config
   ORACLE(sip-config)# 
   

2. Set the load-limit= < Minimum CPU Utilization > [-< CPU Limit for Headroom Calculation >] option as shown in the example below, and then press Enter. The example shows the throttling threshold set to 45% and the variable set to 70. With these settings, the system sets the headroom to 16 and drops all new traffic when the traffic reaches 61%.

   ORACLE(sip-config)# options +load-limit=45-70

   The first value specifies the percent CPU utilization at which the system starts rejecting some SIP requests. The valid range is 15 to 100. The default is 90%.

   The second value specifies the calculation variable the system uses to determine maximum percent CPU utilization and is optional. The default is 100 and the valid range is 15 to 100. If this value is greater than the first value, the system defaults it to 100.

3. Navigate to the system-config.
4. Set the syscpu-load-limit= < Minimum CPU Utilization > [-< CPU Limit for Headroom Calculation >] option as shown in the example below, and then press Enter. This calculation establishes thresholds for overall CPU utilization instead of individual threads. The example shows the throttling threshold set to 45% and the headroom variable set to 70. With these settings, the system sets the headroom to 16 and drops all new traffic when the traffic reaches 61%.

   ORACLE(system-config)#options +syscpu-load-limit=45-70

   The first value specifies the percent CPU utilization at which the system starts rejecting some SIP requests. The valid range is 15 to 100. The default is 90%.

   The second value specifies the calculation variable the system uses to determine maximum percent CPU utilization and is optional. The default is 100 and the valid range is 15 to 100.

   If the value of X is greater than the value of Y, the system defaults Y to 100.

5. Type done.
6. Save and activate your configuration.

1. In Superuser mode, type configure terminal and press Enter.

   ORACLE# configure terminal
   ORACLE(configure)#

2. Type system and press Enter.

   ORACLE(configure)# system
   ORACLE(system)#

3. Type system-config and press Enter.

   ORACLE(system)# system-config
   ORACLE(system-config)#

   From this point, you can configure system-config configuration parameters. To view all system-config parameters, enter a ? at the system prompt.

4. options—Set the options parameter by typing options, a Space, the option name transport-load-limit=<value> with a plus sign in front of it, and then press Enter.

   ORACLE(media-manager)# options +transport-load-limit=80

   Set this option’s value to between 10 and 100 to set the CPU load point at which the transport application threads begin rejecting requests to disassemble packets. A value of 0 disables transport load limiting.

   If you type the option without the plus sign, you will overwrite any previously configured options. In order to append the new options to the realm configuration’s options list, you must prepend the new option with a plus sign as shown in the previous example.

5. Save and activate your configuration.

1. In Superuser mode, type configure terminal and press Enter.

   ORACLE# configure terminal
   ORACLE(configure)#

2. Type media-manager and press Enter to access the media-level configuration elements.

   ORACLE(configure)# media-manager
   ORACLE(media-manager)#

3. Type media-manager and press Enter to begin configuring media over TCP.

   ORACLE(media-manager)# media-manager
   ORACLE(media-manager-config)#

   From this point, you can configure media-manager-config configuration parameters. To view all media-manager-config parameters, enter a ? at the system prompt.

4. options — Set the options parameter by typing options, a Space, the option name media-load-limit=<value> with a plus sign in front of it, and then press Enter.

   ORACLE(media-manager)# options +media-load-limit=80

   Set the option’s value to between 0 and 100 to set the CPU load point at which the media traffic setup begin rejecting requests. The media-load-limit=<value> default is 80. A value of 0 disables media task limiting.

   If you type the option without the plus sign, you will overwrite any previously configured options. In order to append the new options to the realm configuration’s options list, you must prepend the new option with a plus sign as shown in the previous example.

5. Save and activate your configuration.