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VSXi call states timeouts

The VSXi has several call state timeouts that can be configured on a per-resource basis. 

  • No Ring Timeout
  • Ring No Answer Timeout
  • INVITE Response Timeout
  • Maximum Call Duration

No Ring Timeout

When an INVITE receives a response, typically a 100 Trying, this timer will have the VSXi wait until a 180, 183 or 200 OK is received. If no response arrives the call attempt will end with a CANCEL. No Ring Timeout is applied on the egress/termination Trunk ID. 

The default value of No Ring Timeout is 30 seconds. In a peering or wholesale environment this can be adjusted to control post dial delay (PDD). For example, if a carrier typically provides ringing within 5 seconds, you can reduce this to 10 seconds.

By default the cause code mapping of a No Ring Timeout is a 503.

SIP/2.0 503 Service Unavailable
Via: SIP/2.0/UDP 192.188.0.242:55345;received=74.62.23.98;branch=z9hG4bK-524287-1---f0243739cd885461;rport=11723
To: <sip:18885552000@8.38.53.10>
From: <sip:18885550000@8.38.53.10>;tag=c5b7b403
Call-ID: 89373ZmQwOTVkMWI5NGU1YWNjOGQxMmFiM2Q4MTJlYjMzMmE
CSeq: 1 INVITE
Reason: Q.850;cause=18;text="No Ring Timeout"
Content-Length: 0

CDR:

Session 74484-830444860@8.38.53.8,    Release Cause (code) = 0405
    Internal Stack Cause   = 999, No Ring Timeout
    Start           =  Fri Feb  1 13:22:57 2019 GMT-7
    Answer          =  NA GMT-7
    Release         =  Fri Feb  1 13:23:27 2019 GMT-7
    Duration        =  0
    Post Dial Delay (sec) =  30
    Termination Post Dial Delay (msec) =  30000
    Ring Time       =  0
    Media           =  WithMedia

    Orig TID        = 000030,    Proc_SIP
    ANI             = 18885550000,    From = 74.62.23.98
    DNIS            = 18885551000,    To = 8.38.53.10
    RN              = N/A
    Call Leg ID     = 89373OWU2ZWFkYjg1OTcyM2YzNjIxNWI5YTAzOTM4NzhkNjU
    Media IP:UDP    = 192.188.0.242:51960
    Switched IP:UDP = 8.38.53.10:11976
    Codec List      = G.711u_64k,RFC 2833

    Term TID        = 000006,    Proc_SIP
    ANI             = 18885550000,    From = 8.38.53.47
    DNIS            = 18885551000,    To = 8.38.53.128
    RN              = N/A
    Call Leg ID     = 74484-0-830444860@8.38.53.8
    Media IP:UDP    = 0.0.0.0:0
    Switched IP:UDP = 8.38.53.10:11978
    Codec List      = NA

    Routed Digits = 18885551000
    Route Selection = 1,    Final Call Indication = F    OLI = N/A
    CNAM Dipped : Yes      LNP Dipped : No      ERS Dipped : No
    ERS Route Table : 0 , Sequence: 0 , Jurisdiction: 0
    Matched ERS Digits =
    Orig:  Pkt In   = 0,  Pkt Out = 0,  Byte In = 0,  Byte Out = 0,  MOS = 0.0
    Term:  Pkt In   = 0,  Pkt Out = 0,  Byte In = 0,  Byte Out = 0,  MOS = 0.0

It is possible to override this behavior using the Cause Code Profile's Q.850/ISUP/H.323 release code, indicating that an 18 is a 480, for example. Since Cause Code Profile's are effective on the ingress direction, you can modify this mapping to all of your customers, a group of customers or just one customer with the modified Cause Code Profile. 

 

Ring No Answer Timeout

Ring No Answer Time (RNA) is the next timer after a call attempt has received a ring signal. At this stage the VSXi will keep waiting until the call is answered with a 200 OK in response to the original INVITE. 

By default the cause code mapping of a RNA is a 408. The 408 can be modified to another value using Cause Code Profiles (as explained above for No Ring Timeout), except that it will be mapped to Q.850/ISUP code 19.

Generally speaking the RNA is set long enough to give the chance to go to voicemail (typically anywhere between 30 and 60 seconds). 

SIP/2.0 408 Request Timeout
Via: SIP/2.0/UDP 192.188.0.242:55345;received=74.62.23.98;branch=z9hG4bK-524287-1---f292137234144c6e;rport=11723
To: <sip:18587542200@8.38.53.10>;tag=sansay146658rdb18
From: <sip:18885550000@8.38.53.10>;tag=0b601518
Call-ID: 89373ZWU3Mjc1NDNhMzQwM2Q0ZWUwYTdlZjljNDQyYmM2ODU
CSeq: 1 INVITE
Reason: Q.850;cause=19;text="No Answer Timeout"
Content-Length: 0

CDR:

Session 74340-830006520@8.38.53.8,    Release Cause (code) = 0004
    Internal Stack Cause   = 999, Ring No Answer Timeout
    Start           =  Fri Feb  1 13:15:39 2019 GMT-7
    Answer          =  NA GMT-7
    Release         =  Fri Feb  1 13:16:49 2019 GMT-7
    Duration        =  0
    Post Dial Delay (sec) =  10
    Termination Post Dial Delay (msec) =  10040
    Ring Time       =  60
    Media           =  WithMedia

    Orig TID        = 000030,    Proc_SIP
    ANI             = 18885550000,    From = 74.62.23.98
    DNIS            = 18587542200,    To = 8.38.53.10
    RN              = N/A
    Call Leg ID     = 89373ZWU3Mjc1NDNhMzQwM2Q0ZWUwYTdlZjljNDQyYmM2ODU
    Media IP:UDP    = 192.188.0.242:53762
    Switched IP:UDP = 8.38.53.10:11968
    Codec List      = G.711u_64k,RFC 2833

    Term TID        = 000006,    Proc_SIP
    ANI             = 18885550000,    From = 8.38.53.47
    DNIS            = 18587542200,    To = 8.38.53.128
    RN              = N/A
    Call Leg ID     = 74340-0-830006520@8.38.53.8
    Media IP:UDP    = 8.38.53.128:6000
    Switched IP:UDP = 8.38.53.10:11970
    Codec List      = G.711u_64k,RFC 2833

    Routed Digits = 18587542200
    Route Selection = 1,    Final Call Indication = F    OLI = N/A
    CNAM Dipped : Yes      LNP Dipped : No      ERS Dipped : No
    ERS Route Table : 0 , Sequence: 0 , Jurisdiction: 0
    Matched ERS Digits =
    Orig:  Pkt In   = 0,  Pkt Out = 0,  Byte In = 0,  Byte Out = 0,  MOS = 0.0
    Term:  Pkt In   = 0,  Pkt Out = 0,  Byte In = 0,  Byte Out = 0,  MOS = 0.0

INVITE Response Timeout

An INVITE response timeout will happen if the termination didn't provide any type of response to the VSXi's request: no 100 Trying, 18X, 200 OK or any other rejection code (3XX-6XX). 

The VSXi timing will depend on the termination's SIP Profile. This is typically 4 seconds (one second of wait after the initial INVITE, three total resends one second apart). 

Note: It is best common practice to not modify the SIP Profile's default timer/resend values. Please contact Support if your application may require any adjustments. The default values are used almost always. 

By default the VSXi will return a 504 to the origination.  The 504 can be mapped to another cause code, such as a 503 if needed. This will need to be mapped using the SIP-to-SIP mapping in the Cause Code Profile.

 

SIP/2.0 504 Server Timeout
Via: SIP/2.0/UDP 192.188.0.242:55345;received=74.62.23.98;branch=z9hG4bK-524287-1---83a2373efe6c2d30;rport=55345
To: <sip:18585559999@8.38.53.10>
From: <sip:18885550000@8.38.53.10>;tag=49c34b1d
Call-ID: 89373ODMzMDQwOTI4NGE0ZDk1YjZmNTJjYzM1MzQwYjRkN2M
CSeq: 1 INVITE
Content-Length: 0

CDR:

Session 75977-838852940@8.38.53.8,    Release Cause (code) = 0405
    Termination Stack Cause   = 504, INVITE Response Timeout
    Start           =  Fri Feb  1 15:43:06 2019 GMT-7
    Answer          =  NA GMT-7
    Release         =  Fri Feb  1 15:43:22 2019 GMT-7
    Duration        =  0
    Post Dial Delay (sec) =  16
    Termination Post Dial Delay (msec) =  16050
    Ring Time       =  0
    Media           =  WithMedia

    Orig TID        = 000030,    Proc_SIP
    ANI             = 18885550000,    From = 74.62.23.98
    DNIS            = 18585559999,    To = 8.38.53.10
    RN              = N/A
    Call Leg ID     = 89373ODMzMDQwOTI4NGE0ZDk1YjZmNTJjYzM1MzQwYjRkN2M
    Media IP:UDP    = 192.188.0.242:63104
    Switched IP:UDP = 8.38.53.10:12036
    Codec List      = G.711u_64k,RFC 2833

    Term TID        = 000006,    Proc_SIP
    ANI             = 18885550000,    From = 8.38.53.47
    DNIS            = 18585559999,    To = 8.38.53.128
    RN              = N/A
    Call Leg ID     = 75977-0-838852940@8.38.53.8
    Media IP:UDP    = 0.0.0.0:0
    Switched IP:UDP = 8.38.53.10:12038
    Codec List      = NA

    Routed Digits = 18585559999
    Route Selection = 1,    Final Call Indication = F    OLI = N/A
    CNAM Dipped : Yes      LNP Dipped : No      ERS Dipped : No
    ERS Route Table : 0 , Sequence: 0 , Jurisdiction: 0
    Matched ERS Digits =
    Orig:  Pkt In   = 0,  Pkt Out = 0,  Byte In = 0,  Byte Out = 0,  MOS = 0.0
    Term:  Pkt In   = 0,  Pkt Out = 0,  Byte In = 0,  Byte Out = 0,  MOS = 0.0

    Transcoded Media = No
    Orig Media       = RTP , Term Media = RTP

Maximum Call Duration

As its name suggests, the Maximum Call Duration (MCD) will trigger on answered calls upon hitting the configured MCD. Since the VSXi keeps two legs, the shortest MCD will be considered if the origination and termination Trunk IDs/Resources have different MCD.

For example, if Trunk ID 30 (Origination) has MCD of 1800s and Trunk ID 6 (Term) has MCD of 3600s, this particular session's MCD will honor the shortest MCD, 1800s.

The VSXi will tear down both legs of the call upon hitting the MCD with a Normal BYE.

BYE sip:18885550000@192.188.0.242:55345 SIP/2.0
Via: SIP/2.0/UDP 8.38.53.10:5060;branch=z9hG4bK2sansay149667rdb11
To: <sip:18885550000@8.38.53.10>;tag=eaaf1a46
From: <sip:18885551000@8.38.53.10>;tag=sansay149667rdb11
Call-ID: 89373ZDc5MzI1N2VhODcyMGE2NjFiYWM0ZWI5N2QxNzY3YWY
CSeq: 2 BYE
Reason: Q.850;cause=16;text="Duration Exceeded"
Max-Forwards: 70
Content-Length: 0

Note: Have in mind that despite the Protocol Release Cause Code not being a 200 OK, this call is considered a billable call. The internal Release Cause Code (0001) should be used to track all completed calls. 

Session 76058-839510390@8.38.53.8,    Release Cause (code) = 0001
    Internal Stack Cause   = 999, Maximum Duration Exceeded
    Start           =  Fri Feb  1 15:54:04 2019 GMT-7
    Answer          =  Fri Feb  1 15:54:12 2019 GMT-7
    Release         =  Fri Feb  1 15:54:42 2019 GMT-7
    Duration        =  30
    Post Dial Delay (sec) =  8
    Termination Post Dial Delay (msec) =  8030
    Ring Time       =  1
    Media           =  WithMedia

    Orig TID        = 000030,    Proc_SIP
    ANI             = 18885550000,    From = 74.62.23.98
    DNIS            = 18585559999,    To = 8.38.53.10
    RN              = N/A
    Call Leg ID     = 89373OGM4OGM0NjQzODQzNmRjN2FkYzQwMTUxMjkwMDUwMTY
    Media IP:UDP    = 192.188.0.242:51512
    Switched IP:UDP = 8.38.53.10:12044
    Codec List      = G.711u_64k,RFC 2833

    Term TID        = 000006,    Proc_SIP
    ANI             = 18885550000,    From = 8.38.53.47
    DNIS            = 18585559999,    To = 8.38.53.128
    RN              = N/A
    Call Leg ID     = 76058-0-839510390@8.38.53.8
    Media IP:UDP    = 8.38.53.128:6000
    Switched IP:UDP = 8.38.53.10:12046
    Codec List      = G.711u_64k

    Routed Digits = 18585559999
    Route Selection = 1,    Final Call Indication = F    OLI = N/A
    CNAM Dipped : Yes      LNP Dipped : No      ERS Dipped : No
    ERS Route Table : 0 , Sequence: 0 , Jurisdiction: 0
    Matched ERS Digits =
    Orig:  Pkt In   = 0,  Pkt Out = 0,  Byte In = 0,  Byte Out = 0,  MOS = 0.0
    Term:  Pkt In   = 0,  Pkt Out = 0,  Byte In = 0,  Byte Out = 0,  MOS = 0.0

    Transcoded Media = No
    Orig Media       = RTP , Term Media = RTP

3 replies

null
    • Anuprasad_Kummali
    • 5 yrs ago
    • Reported - view

    Is there any RTP / RTCP Timeout options ?

      • cperez
      • 5 yrs ago
      • Reported - view

      Anuprasad Kummali we do not support RTP / RTCP timeouts. In general SIP session timers are more reliable to detect hung endpoints/sessions and prevent false positives. 

    • Glen_Gerhard
    • 5 yrs ago
    • Reported - view

    Is there a guide as to which Timeouts count towards a Fail Call? ie, something like a Ring No Answer Timeout call is considered OK or is it a failure? Similarly a No Ring Timeout should certainly be considered a failed call. I'm curious from the aspect of the statistics on the GUI, what calls are considered as part of the FCR?