Explanation of "show sub summary" Counts

Introduction

This document describes what appears to be an inconsistency in subscriber counts reported with the "show sub summary" command. Normally the count of all the subscriber types from "show sub summary" add up to the "Total Subscribers" count at the top. However, the existence of both dedicated and default bearers for subscribers and use of certain qualifiers can result in the counts of various subscriber types that do not match what is expected for the "Total Subscribers".

Explanation via Examples

Count dedicated and default bearers for a VoLTE subscriber

In the case of Voice over Long Term Evolution (VoLTE), there is a dedicated and default bearer for the IP Multimedia System (IMS) Application Point Name (APN) that is essential for the setup of all VoLTE calls. "Show sub summ" increments by one for the "Total Subscribers" field for each unique subscriber, even though each subscriber has two bearers. But, the fact that each subscriber has two bearers IS captured in the subsections of the CLI. For example, note here that the count of pgw-gtp-ipv6 represents the count of both the dedicated and default bearers for the IMS APN, while the Total count only captures the fact that both of the bearers are for the same IMS APN. This is further confirmed by the pgw-only qualifier which actually lists out the individual bearers, but like the non pgw-only version, only counts a subscriber once per APN via the Total field.

These examples are taken from a Packet Data Network Gateway (PGW) that includes both LTE and Enhanced High Rate Packet Data (eHRPD) call types.

Note that pgw-gtp-ipv6 (LTE) + pgw-pmip-ipv6 (eHRPD) - Total Dedicated Bearers = Total Subs

[local]PGW> show sub summ apn ims
Sunday August 23 03:58:07 UTC 2015
 
Total Subscribers:             1851827   
Active:                        1851827       Dormant:                   0
hsgw-ipv4-ipv6:                0             pgw-pmip-ipv6:             285069 
pgw-pmip-ipv4:                 0             pgw-pmip-ipv4-ipv6:        0 
pgw-gtp-ipv6:                  1567307       pgw-gtp-ipv4:              0  

[local]PGW> show sub pgw-only summ apn ims
Sunday August 23 03:58:08 UTC 2015
 
 Total Subscribers        : 1851820   
 Total Home               : 1851816       Total Visitors            : 4
 Total Roamers            : 0             Total S6b Assume Positive : 0
 Total Bearers            : 1567308   
 Total Default Bearers    : 1566761       Total Dedicated Bearers   : 547

 Total PDNs by RAT-Type
 EUTRAN                   : 1566761       UTRAN                     : 0
 GERAN                    : 0             WLAN                      : 0
 OTHER                    : 285059    

 pmip-pdn-type-ipv4       : 0         
 pmip-pdn-type-ipv6       : 285059    
 pmip-pdn-type-ipv4-ipv6  : 0         
 gtp-pdn-type-ipv4        : 0         
 gtp-pdn-type-ipv6        : 1567308 

This principal even applies to "show sub" summ without any qualifiers.

65 + 1567327 + 285074 + 235124 + 1653 = 3430145 - 547 (dedicated bearers) = 3429598 ~= 3429614

[local]PGW> show sub summ
Sunday August 23 03:58:07 UTC 2015

Total Subscribers:             3429614   
Active:                        3429614       Dormant:                  0  
LAPI Devices:                  0         
pdsn-simple-ipv4:              0             pdsn-simple-ipv6:         0
pdsn-mobile-ip:                0             ha-mobile-ipv6:           0
hsgw-ipv6:                     0             hsgw-ipv4:                0 
hsgw-ipv4-ipv6:                0             pgw-pmip-ipv6:            285074
pgw-pmip-ipv4:                 65            pgw-pmip-ipv4-ipv6:       235124
pgw-gtp-ipv6:                  1567327       pgw-gtp-ipv4:             1653
pgw-gtp-ipv4-ipv6:             1340902       sgw-gtp-ipv6:             0 

This is even clearer when you qualify by just VoLTE subscribers that pass voice data using QCI = 1 via the dedicated bearer. In this case note that the pgw-gtp-ipv6 is roughly double the Total Subscribers, since it counts both the dedicated and default bearers for each VOLTE subscriber.

[local]PGW> show sub summ apn ims qci 1
Sunday August 23 04:34:57 UTC 2015
 
Total Subscribers:             302       
Active:                        302           Dormant:                0         
LAPI Devices:                  0         
pdsn-simple-ipv4:              0             pdsn-simple-ipv6:       0         
pdsn-mobile-ip:                0             ha-mobile-ipv6:         0         
hsgw-ipv6:                     0             hsgw-ipv4:              0         
hsgw-ipv4-ipv6:                0             pgw-pmip-ipv6:          0         
pgw-pmip-ipv4:                 0             pgw-pmip-ipv4-ipv6:     0         
pgw-gtp-ipv6:                  605           pgw-gtp-ipv4:           0  

[local]PGW> show sub pgw-only summ apn ims qci 1
Sunday August 23 04:34:58 UTC 2015

 Total Subscribers        : 302       
 Total Home               : 302           Total Visitors            : 0         
 Total Roamers            : 0             Total S6b Assume Positive : 0         
 Total Bearers            : 605       
 Total Default Bearers    : 302           Total Dedicated Bearers   : 303       

 Total PDNs by RAT-Type
 EUTRAN                   : 302           UTRAN                     : 0         
 GERAN                    : 0             WLAN                      : 0         
 OTHER                    : 0         

 pmip-pdn-type-ipv4       : 0         
 pmip-pdn-type-ipv6       : 0         
 pmip-pdn-type-ipv4-ipv6  : 0         
 gtp-pdn-type-ipv4        : 0         
 gtp-pdn-type-ipv6        : 605

Count dedicated and default bearers which share the same callid

A related example is when you list subscribers by callid. A single callid represents all the bearers of a given APN, while all the bearers (2) that share that callid get listed/counted individually. Meanwhile the Total field only increments once in order to represent all those bearers of an APN. In this example, the IMS default bearer ID = 5 and the IMS dedicated bearer ID = 7.

[local]PGW> show sub callid 0000d532
Sunday August 23 04:39:54 UTC 2015

vvvvvv CALLID   MSID            USERNAME               IP                                 TIME-IDLE
------ -------- --------------- ---------------------- ----------------------------- ---------
YTCNAT 0000d532 320490143033837 0320490143033837@nai.epc.mnc490.mcc320.3gppnetwork.org 2600:5555:801a:1bee::d5:3201  00h38m02s
YTCNAT 0000d532 320490143033837 0320490143033837@nai.epc.mnc490.mcc320.3gppnetwork.org 2600:5555:801a:1bee::d5:3201  00h38m02s

[local]PGW> show sub summ callid 0000d532
Sunday August 23 04:39:56 UTC 2015

Total Subscribers:             1         
Active:                        1             Dormant:                       0         
LAPI Devices:                  0         
pdsn-simple-ipv4:              0             pdsn-simple-ipv6:              0         
pdsn-mobile-ip:                0             ha-mobile-ipv6:                0         
hsgw-ipv6:                     0             hsgw-ipv4:                     0         
hsgw-ipv4-ipv6:                0             pgw-pmip-ipv6:                 0         
pgw-pmip-ipv4:                 0             pgw-pmip-ipv4-ipv6:            0         
pgw-gtp-ipv6:                  2             pgw-gtp-ipv4:                  0 

[local]PGW> show sub pgw-only callid 0000d532
Sunday August 23 04:39:57 UTC 2015

vvvvvv CALLID   IMSI/IMEI         v   v IP                            APN              TIME-IDLE
------ -------- ----------------- --- - ----------------------------- ---------------- ---------
YECHDN 0000d532 3204900143033837   005 L 2600:5555:801a:1bee::d5:3201  ims           00h38m05s
YECHEN 0000d532 3204900143033837   007 L 2600:5555:801a:1bee::d5:3201  ims           00h38m05s

[local]PGW> show sub pgw-only summ callid 0000d532
Sunday August 23 04:39:59 UTC 2015

 Total Subscribers        : 1         
 Total Home               : 1             Total Visitors            : 0         
 Total Roamers            : 0             Total S6b Assume Positive : 0         
 Total Bearers            : 2         
 Total Default Bearers    : 1             Total Dedicated Bearers   : 1         

 Total PDNs by RAT-Type
 EUTRAN                   : 1             UTRAN                     : 0         
 GERAN                    : 0             WLAN                      : 0         
 OTHER                    : 0         

 pmip-pdn-type-ipv4       : 0         
 pmip-pdn-type-ipv6       : 0         
 pmip-pdn-type-ipv4-ipv6  : 0         
 gtp-pdn-type-ipv4        : 0         
 gtp-pdn-type-ipv6        : 2  

Mix of qualifiers that apply to dedicated/default bearers versus all subscribers

Finally, probably the most confusing example is where multiple qualifiers are used in succession that apply at the bearer level as well as to the subscriber overall. In this example, a third qualifier is added to narrow subscribers that have been connected for greater than a day (86400 seconds). Since this example also uses the QCI 1 that represents VoLTE subscribers, it might be expected that the hit list would be empty because how many people are on a call for greater than 24 hours? But the result is not a true AND operation as might be expected. That is, the result is not the IMS VoLTE sessions that have been connected for greater than a day, as that number is likely 0. Instead, the result is all IMS subscribers that have a VoLTE session and where either the default IMS or dedicated (VoLTE) IMS session has been up for greater than a day (the former of which would not be uncommon).

In this output, the connected-time greater-than qualifier does limit the output to subscribers that have been connected greater than a day over the default IMS bearer, compared to without the qualifier which does not consider call connected time.

[local]PGW> show sub summ apn ims qci 1 connected-time greater-than 86400
Sunday August 23 05:18:23 UTC 2015

Total Subscribers:             113       
Active:                        113           Dormant:                       0
LAPI Devices:                  0         
pdsn-simple-ipv4:              0             pdsn-simple-ipv6:              0
pdsn-mobile-ip:                0             ha-mobile-ipv6:                0
hsgw-ipv6:                     0             hsgw-ipv4:                     0
hsgw-ipv4-ipv6:                0             pgw-pmip-ipv6:                 0
pgw-pmip-ipv4:                 0             pgw-pmip-ipv4-ipv6:            0      
pgw-gtp-ipv6:                  226           pgw-gtp-ipv4:                  0

[local]PGW> show sub summ apn ims qci 1 
Sunday August 23 05:18:52 UTC 2015

Total Subscribers:             248       
Active:                        248           Dormant:                       0
LAPI Devices:                  0         
pdsn-simple-ipv4:              0             pdsn-simple-ipv6:              0
pdsn-mobile-ip:                0             ha-mobile-ipv6:                0
hsgw-ipv6:                     0             hsgw-ipv4:                     0
hsgw-ipv4-ipv6:                0             pgw-pmip-ipv6:                 0
pgw-pmip-ipv4:                 0             pgw-pmip-ipv4-ipv6:            0
pgw-gtp-ipv6:                  497           pgw-gtp-ipv4:                  0

Here is an example with full output for a given subscriber that meets the criteria of the connected time greater than a day.

Note: The connect time for the Internet APN default is within a few minutes after you enter the command, so you can be sure that it is the default IMS bearer that meets the criteria of connected greater than a day (connected Fri Aug 7 20:01:23) which results in this subscriber being reported.

[local]PGW> show sub apn ims qci 1 connected-time greater-than 86400
Monday August 10 12:04:29 UTC 2015
vvvvvv CALLID   MSID            USERNAME               IP                                 TIME-IDLE
------ -------- --------------- ---------------------- ----------------------------- ---------
YTCNAT 00eff501 320490127668665 0320490127668665@nai.epc.mnc490.mcc320.3gppnetwork.org 2600:5555:8001:9ccb::eff5:101 00h00m00s 
 
[local]PGW> show sub pgw-only full imsi 320490127668665
Monday August 10 12:06:38 UTC 2015
 
Username: 0320490127668665@nai.epc.mnc490.mcc320.3gppnetwork.org
  Subscriber Type : Home
  Status          : Online/Active
  State           : Connected
  Connect Time    : Fri Aug  7 20:01:23 2015
 
  Auto Delete     : No
 
  Idle time       : 00h00m00s
  MS TimeZone     : -4:00               Daylight Saving Time: +1 hour
 
  Access Type: gtp-pdn-type-ipv6         Network Type: IPv6
  Access Tech: eUTRAN                    pgw-service-name: PGW1
  Callid: 00eff501                       IMSI: 320490127668665
  MSISDN: 16036860864
  Interface Type: S5S8GTP                Low Access Priority: N/A
  Emergency Bearer Type: N/A
  IMS-media Bearer: No
  S6b Auth Status: Enabled
  Access Peer Profile: default
  Acct-session-id (C1): 42AE14C2013B7181
  ThreeGPP2-correlation-id (C2): 01C250B4 / 0t-G0QsS
  Card/Cpu: 1/1                          Sessmgr Instance: 4
 
  Bearer Type: Default                   Bearer-Id: 5
  Bearer State: Active                        
  IP allocation type: N/A 
  IPv6 allocation type: local pool         
  IP address: 2600:5555:8001:9ccb::eff5:101
...
  S5/S8/S2b/S2a-APN: ims                   
  SGi-APN:   ims         
 
  Bearer QoS:
   QCI: 5
...
 
Username: 0320490127668665@nai.epc.mnc490.mcc320.3gppnetwork.org
  Subscriber Type : Home
  Status          : Online/Active
  State           : Connected
  Connect Time    : Mon Aug 10 11:52:51 2015
 
  Auto Delete     : No
 
  Idle time       : 00h00m00s
  MS TimeZone     : -4:00               Daylight Saving Time: +1 hour
 
  Access Type: gtp-pdn-type-ipv6         Network Type: IPv6
  Access Tech: eUTRAN                    pgw-service-name: PGW1
  Callid: 00eff501                       IMSI: 320490127668665
  MSISDN: 16036860864
  Interface Type: S5S8GTP                Low Access Priority: N/A
  Emergency Bearer Type: N/A
  IMS-media Bearer: Yes
  S6b Auth Status: Enabled
  Access Peer Profile: default
  Acct-session-id (C1): 42AE14C2013E4AF6
  ThreeGPP2-correlation-id (C2): 01C250B4 / 0t-G0QsS
  Card/Cpu: 1/1                          Sessmgr Instance: 4
 
  Bearer Type: Dedicated                 Bearer-Id: 7
  Bearer State: Active                        
  IP allocation type: N/A 
  IPv6 allocation type: local pool         
  IP address: 2600:5555:8001:9ccb::eff5:101
...
  S5/S8/S2b/S2a-APN: ims                   
  SGi-APN:   ims                   
 
  Bearer QoS:
   QCI: 1
 
Username: 0320490127668665@nai.epc.mnc490.mcc320.3gppnetwork.org
  Subscriber Type : Home
  Status          : Online/Active
  State           : Connected
  Connect Time    : Mon Aug 10 11:51:24 2015
 
  Auto Delete     : No
 
  Idle time       : 00h15m14s
  MS TimeZone     : -4:00               Daylight Saving Time: +1 hour
 
  Access Type: gtp-pdn-type-ipv4-ipv6    Network Type: IPV4+IPv6
  Access Tech: eUTRAN                    pgw-service-name: PGW1
  Callid: 00f2c514                       IMSI: 320490127668665
  MSISDN: 15556860864
  Interface Type: S5S8GTP                Low Access Priority: N/A
  Emergency Bearer Type: N/A
  IMS-media Bearer: No
  S6b Auth Status: Enabled
  Access Peer Profile: default
  Acct-session-id (C1): 42AE14C2013E4AC5
  ThreeGPP2-correlation-id (C2): 01C520A2 / 0umaajjh
  Card/Cpu: 1/1                          Sessmgr Instance: 4
 
  Bearer Type: Default                   Bearer-Id: 6
  Bearer State: Active                        
  IP allocation type: local pool         
  IPv6 allocation type: local pool         
  IP address: 2600:5555:b027:b408::f2c5:1401, 100.84.110.26
...
  S5/S8/S2b/S2a-APN: internet              
  SGi-APN:   internet              
  
  Bearer QoS:
   QCI: 8
   ARP: 0x069
 
Total subscribers matching specified criteria: 3