Debug ISDN q931 help: What are Channel 30 and 35 on a QSIG trunk?

calicolin1 · ‎07-08-2015

I have two serial interfaces on a 3925 configured as QSIG trunks connecting to a Nortel Meridian. The config for each interface is given below. There are 23 B channels plus 1 D channel on each trunk. But according to the debug isdn q931, I see calls taking Channels 30 and 35? What gives?

interface Serial0/0/2:23
description To-Nortel-Loop-6
no ip address
encapsulation hdlc
isdn switch-type primary-qsig
isdn timer T310 120000
isdn protocol-emulate network
isdn incoming-voice voice
isdn bind-l3 ccm-manager
no cdp enable

interface Serial0/0/3:23
description To-Nortel-Loop-7
no ip address
encapsulation hdlc
isdn switch-type primary-qsig
isdn timer T310 120000
isdn protocol-emulate network
isdn incoming-voice voice
isdn bind-l3 ccm-manager
no cdp enable

Jul 8 17:30:35.408: ISDN Se0/0/2:23 Q931: TX -> SETUP pd = 8 callref = 0x7AC2

Sending Complete

Bearer Capability i = 0xA880

Standard = ISO/IEC

Transfer Capability = Unrestricted Digital

Transfer Mode = Circuit

Transfer Rate = Packet - not specified

Channel ID i = 0xAC

Exclusive, Channel 35

Facility i = 0x9FAA06800100820100A11802025CD7020151300FA50A0A0100120536393533300A0120

Calling Party Number i = 0x0081, '42'

Plan:Unknown, Type:Unknown

Called Party Number i = 0x80, '9530'

Plan:Unknown, Type:Unknown

Jul 8 17:30:35.476: ISDN Se0/0/2:23 Q931: RX <- CALL_PROC pd = 8 callref = 0xFAC2

Channel ID i = 0xAC

Exclusive, Channel 30

Jul 8 17:30:35.516: ISDN Se0/0/3:23 Q931: RX <- SETUP pd = 8 callref = 0x0E38

Sending Complete

Bearer Capability i = 0xA880

Standard = ISO/IEC

Transfer Capability = Unrestricted Digital

Transfer Mode = Circuit

Transfer Rate = Packet - not specified

Channel ID i = 0xAC

Exclusive, Channel 35

Facility i = 0x9FAA06800100820100A11802025CD7020151300FA50A0A0100120536393533300A0120

Calling Party Number i = 0x80, '42'

Plan:Unknown, Type:Unknown

Called Party Number i = 0x89, '69530'

Plan:Private, Type:Unknown

Jul 8 17:30:35.524: ISDN Se0/0/3:23 Q931: TX -> CALL_PROC pd = 8 callref = 0x8E38

Channel ID i = 0xAC

Exclusive, Channel 0

Jul 8 17:30:35.528: ISDN Se0/0/3:23 Q931: TX -> SETUP pd = 8 callref = 0x5352

Sending Complete

Bearer Capability i = 0xA880

Standard = ISO/IEC

Transfer Capability = Unrestricted Digital

Transfer Mode = Circuit

Transfer Rate = Packet - not specified

Channel ID i = 0xAC

Exclusive, Channel 35

Facility i = 0x9FAA06800100820100A11802025CD7020151300FA50A0A0100120536393533300A0120

Calling Party Number i = 0x0083, '4242'

Plan:Unknown, Type:Unknown

Called Party Number i = 0x80, '9530'

Plan:Unknown, Type:Unknown

Jul 8 17:30:35.648: ISDN Se0/0/3:23 Q931: RX <- CALL_PROC pd = 8 callref = 0xD352

Channel ID i = 0xAC

Exclusive, Channel 30

Mohammed al Baqari · ‎07-09-2015

Hi,

From the logs I can see that you are using T1 PRI. By default Cisco PRI routers use descending channel selection. This means that channels 30 is your 1st channel which the IOS router is using to communicate with your telco. Channel 35 is the channel selected by your telco to signal your router. Usually the telcos use NFAS to provide large pool of channels.

calicolin1 · ‎07-09-2015

But there are only 23 channels on each PRI. NFAS is not implemented here. I must be missing something.. how can 30 and 35 be used on a 23 channel PRI?

Mohammed al Baqari · ‎07-09-2015

Can you share the output of show inventory from your router?

calicolin1 · ‎07-09-2015

sh inventory
NAME: "CISCO3925-CHASSIS", DESCR: "CISCO3925-CHASSIS"
PID: CISCO3925-CHASSIS , VID: V02, SN: FTX...

NAME: "Cisco Services Performance Engine 100 for Cisco 3900 ISR on Slot 0", DESCR: "Cisco Services Performance Engine 100 for Cisco 3900 ISR"
PID: C3900-SPE100/K9 , VID: V06 , SN: FOC...

NAME: "VWIC3-4MFT-T1/E1 - 4-Port RJ-48 Multiflex Trunk - T1/E1 on Slot 0 SubSlot 0", DESCR: "VWIC3-4MFT-T1/E1 - 4-Port RJ-48 Multiflex Trunk - T1/E1"
PID: VWIC3-4MFT-T1/E1 , VID: V01 , SN: FOC...

NAME: "PVDM3 DSP DIMM with 128 Channels on Slot 0 SubSlot 4", DESCR: "PVDM3 DSP DIMM with 128 Channels"
PID: PVDM3-128 , VID: V01 , SN: FOC...

NAME: "C3900 AC Power Supply 1", DESCR: "C3900 AC Power Supply 1"
PID: PWR-3900-AC , VID: V04 , SN: QCS...

NAME: "C3900 AC Power Supply 2", DESCR: "C3900 AC Power Supply 2"
PID: PWR-3900-AC , VID: V04 , SN: QCS...

Wilson Samuel · ‎07-09-2015

This is really interesting, could you please post the following outputs:

1. sh isdn status

2. sh run from the router

Regards

calicolin1 · ‎07-09-2015

sh isdn status
Global ISDN Switchtype = primary-ni

%Q.931 is backhauled to CCM MANAGER 0x0003 on DSL 0. Layer 3 output may not apply

ISDN Serial0/0/2:23 interface
******* Network side configuration *******
dsl 0, interface ISDN Switchtype = primary-qsig
**** Master side configuration ****
L2 Protocol = Q.921 0x0000 L3 Protocol(s) = CCM MANAGER 0x0003
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 0, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x807FFFFF
Number of L2 Discards = 0, L2 Session ID = 70

%Q.931 is backhauled to CCM MANAGER 0x0003 on DSL 1. Layer 3 output may not apply

ISDN Serial0/0/3:23 interface
******* Network side configuration *******
dsl 1, interface ISDN Switchtype = primary-qsig
**** Master side configuration ****
L2 Protocol = Q.921 0x0000 L3 Protocol(s) = CCM MANAGER 0x0003
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 0, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 1 CCBs = 0
The Free Channel Mask: 0x807FFFFF
Number of L2 Discards = 0, L2 Session ID = 164
Total Allocated ISDN CCBs = 0

sh run
Building configuration...

Current configuration : 6543 bytes
!
!
version 15.2
service timestamps debug datetime msec localtime
service timestamps log datetime localtime
service password-encryption
!
hostname vg1...
!
boot-start-marker
boot system flash:c3900-universalk9-mz.SPA.152-4.M7.bin
boot system flash:c3900-universalk9-mz.SPA.152-4.M6a.bin
boot-end-marker
!
!
card type t1 0 0
logging buffered 8000000
enable secret 5 $1$
!
aaa new-model
!
!
aaa group server tacacs+ tacgroup
server 172.
!
!
!
!
!
!
aaa session-id common
clock timezone PST -8 0
clock summer-time PDT recurring 2 Sun Mar 2:00 2 Sun Nov 2:00
network-clock-participate wic 0
network-clock-select 1 T1 0/0/0
network-clock-select 2 T1 0/0/1
network-clock-select 3 T1 0/0/2
network-clock-select 4 T1 0/0/3
!
!

ip cef
!

no ipv6 cef
!
multilink bundle-name authenticated
!
!
!
!
isdn switch-type primary-ni
!
voice-card 0
!
!
!
voice service voip
fax protocol t38 version 0 ls-redundancy 0 hs-redundancy 0 fallback none
sip
bind control source-interface GigabitEthernet0/0
bind media source-interface GigabitEthernet0/0
!
!
!
!
voice translation-rule 1
rule 1 /^42/ //
!
!
voice translation-profile Voice
translate called 1
!
!
!
license udi pid C3900-SPE100/K9 sn FOC18349XQG
hw-module pvdm 0/0
!
!
!
!
redundancy
!
!
!
!
!
controller T1 0/0/0
shutdown
cablelength long 0db
!
controller T1 0/0/1
shutdown
cablelength long 0db
!
controller T1 0/0/2
cablelength long 0db
pri-group timeslots 1-24 service mgcp
description Nortel Loop 40
!
controller T1 0/0/3
cablelength long 0db
pri-group timeslots 1-24 service mgcp
description Nortel Loop 41
!
!
class-map match-any AutoQoS-VoIP-RTP-Trust
match ip dscp ef
class-map match-any AutoQoS-VoIP-Control-Trust
match ip dscp cs3
match ip dscp af31
!
policy-map AutoQoS-Policy-Trust
class AutoQoS-VoIP-RTP-Trust
priority percent 70
class AutoQoS-VoIP-Control-Trust
bandwidth percent 5
class class-default
fair-queue
!
!
!
!
!
!
!
!
!
!
interface Embedded-Service-Engine0/0
no ip address
!
interface GigabitEthernet0/0
description To LAN
ip address 172.30.189.101 255.255.255.0
ip pim sparse-dense-mode
duplex auto
speed auto
service-policy output AutoQoS-Policy-Trust
!
interface GigabitEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface GigabitEthernet0/2
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/2:23
description To-Nortel-Loop-40
no ip address
encapsulation hdlc
isdn switch-type primary-qsig
isdn timer T310 120000
isdn protocol-emulate network
isdn incoming-voice voice
isdn bind-l3 ccm-manager
no cdp enable
!
interface Serial0/0/3:23
description To-Nortel-Loop-41
no ip address
encapsulation hdlc
isdn switch-type primary-qsig
isdn timer T310 120000
isdn protocol-emulate network
isdn incoming-voice voice
isdn bind-l3 ccm-manager
no cdp enable
!
ip forward-protocol nd
!
ip http server
ip http authentication local
ip http secure-server
ip http timeout-policy idle 60 life 86400 requests 10000
!
ip route 0.0.0.0 0.0.0.0 172.
!
logging trap debugging
logging host 172.
!
nls resp-timeout 1
cpd cr-id 1
!
!
!
!
control-plane
!
!
voice-port 0/0/2:23
!
voice-port 0/0/3:23
!
!
!
!
ccm-manager fallback-mgcp
ccm-manager redundant-host ucmsub2
ccm-manager mgcp
no ccm-manager fax protocol cisco
ccm-manager music-on-hold
!
mgcp
mgcp call-agent ucmsub1 2427 service-type mgcp version 0.1
mgcp dtmf-relay voip codec all mode out-of-band
mgcp rtp unreachable timeout 1000 action notify
mgcp modem passthrough voip mode nse
mgcp package-capability rtp-package
mgcp package-capability sst-package
mgcp package-capability pre-package
no mgcp package-capability res-package
no mgcp timer receive-rtcp
mgcp sdp simple
mgcp validate domain-name
mgcp fax t38 inhibit
mgcp rtp payload-type g726r16 static
!
mgcp profile default
!
!
dial-peer voice 1 pots
translation-profile incoming Voice
service mgcpapp
port 0/0/2:23
!
dial-peer voice 2 pots
translation-profile incoming Voice
service mgcpapp
port 0/0/3:23
!
!
sip-ua
timers trying 100
!
!
!
gatekeeper
shutdown
!
!
alias configure e end
alias exec c configure term
alias exec sr show run
alias exec sb show ip int br
!
line con 0
line aux 0
line 2
no activation-character
no exec
transport preferred none
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
line vty 0 4
exec-timeout 0 0
privilege level 15
transport input telnet ssh
line vty 5 15
exec-timeout 30000 0
privilege level 15
transport input telnet ssh
!
scheduler allocate 20000 1000
ntp server time1.
!
end

Wilson Samuel · ‎07-09-2015

Certainly seen for the first time about the channel numbers.

Have you tried to reload and see if it makes any difference?

Mohammed al Baqari · ‎07-10-2015

Hi,

In fact in my initial response, I was under impression that it is E1 instead of T1 which made it was normal to me to see channel 30. But with T1 this is very confusing.

Can you share the output of you CUCM MGCP configuration? Also, try to reload the router as Wilson mentioned.