Types of
Signalling
1) Ground start signalling:
2) Supervisory signalling:
off hook--connection between ring and tip wires-closed
circuit
on hook--open circuit
Ringing
3) Information signalling:
Dial tone , Busy, ringback, congestion, Re-order, receiver
off hook
4) Address signalling:
DTMF, Pluse
General Information
Tip ---->positive side of connection
Ring---->negative side of connection
Normally telephone is open circuit
Loop start signalling--->when phone lifted, the phone
connects two wires causing current to flow from central office
Glare occures in Loop start--Glare ----->when u pick the
phone to dial number and simultaneously an incoming call comes and before it
has the chance to ring.
Digital Trunks:
CAS--Common associated signalling --signalling information
is transmitted using same bandwidth as voice.
CAS is sometimes called robbed-bit signaling because user
bandwidth is robbed by the network for signaling.
CCS--Common channel signalling --a separate channel is allocated
for signalling part
T1 & E1
T1: Uses TDM to transmit digital data over 24 voice channels
using CAS. There is no need for signalling channel since for CAS signalling is
transferred with data channel itself.
CAS Provides receipt and capture of DNIS(dialed number
identification service) and ANI(automatic number identification)
The most common signalling used with T1 CAS is E&M
signalling
E1: Uses TDM to transmit digital data over 30 voice channels
using either CAS or CCS.
ISDN: Circuit switched telephone network system allowed to
digital transmission of voice and data over ordinary copper wires.
ISDN BRI :128 kb/s ;2 B channels; 1 D channel
T1 PRI :1.5Mbps; 23 B channels ; 1 D channel
PRI NFAS : Multiple ISDN PRI interfaces controlled by single
D channel.
QSIG: Interopeartion of PBX from different vendors.
Three types of
digital voice circuits are available
1)T1 uses TDM to transmit 24 voice channels using CAS
2)E1 uses to transmit 30 voice channles using either CAS or
CCS
3)ISDN: A circuited swicthed telephone network using CCS
Ø
BRI: 2 B (Bearer) channels and 1 D (Delta)
channel
Ø
T1 PRI: 23 B channels and 1 D channel
Ø
E1 PRI: 30 B channels and 1 D channel
Channels are known as DS0 channels, The ds0-group command
creates a logical voice port (a DS0 group) from some or all of the DS0 channels
Two main types of
CAS are
T1 CAS
E1 R2 Trunk
T1 CAS:
The type of signaling most commonly used with T1 CAS is
E&M signaling
The main disadvantage of CAS signaling is its use of user
bandwidth to perform these signaling functions.
The voice device running the T1 line uses the eighth bit on
every sixth FRAME in each T1 channel (DS0) for signalling.
There are 24 Frames in a T1 Extendede super Frame, the
process of signalling occurs for every sixth frame. 12 frames in super frame.
Each DSO = 8 bits
24 DS0 = 8*24 +1 bit =193 bits ( 1 bit added was for framing
bit)
Digital T1 lines send 8000 of these 193-bit frames every
second
8000*193 =1.5444Mbps
E1 R2
Ø
A multiframe consists of 16 consecutive 256-bit
frames.
Ø
Each frame carries 32 time slots.
Ø
The first time slot is used exclusively for
frame synchronization.
Ø
Time slots 2 to 16 and 18 to 32 carry the actual
voice traffic, and time slot 17 is used for R2 signaling.
Ø
16 Frames == Multi frame in E1 R2
Ø
1st frame--- time slot 17 is to declare the Frame
as multiframe.
Ø
2. Frame, Time slot 17: Signaling for time slots
2 and 18
Ø
3. Frame, Time slot 17: Signaling for time slots
3 and 19
Ø
It goes on like tat
ISDN:
ISDN comprises digital telephony and data-transport services
offered by regional telephonecarriers.
ISDN involves the digitization of the telephone network,
which permits voice, data, text, graphics, music, video, and other source
material to be transmitted overexisting telephone wires.
In contrast to the CAS and R2 signaling, which provide only
DNIS, ISDN offers additional supplementary services such as Call Waiting and Do
Not Disturb (DND).
ISDN applications include high-speed image applications
(such as Group IV facsimile), additional telephone lines in homes to serve the
telecommuting industry, high-speed file transfer, and video conferencing. Voice
service is also an application for ISDN.
ISDN BRI: 2 bearer channel(64kbps) ( for voice traffic)+ 1 D
channel (16kbps)(D channel for signalling)
ISDN PRI: 23 B + 1 D(64kbps) in north america and 30 B +1 D
in rest of the world
T1 PRI: Use this interface to designate North American ISDN
PRI with 23 B channels and one CCS channel
E1 PRI: Use this interface to designate European ISDN PRI
with 30 B channels, one CCS channel, and one framing channel.
ISDN-PRI Nonfacility Associated Signaling (NFAS): Multiple
ISDN PRI interfaces controlled by single D channel.
Benefits of ISDN:
ISDN has a built-in call control protocol known as ITU-T
Q.931.
ISDN supports call waiting, call forwarding,speed dialing
T1 line encoding are B8ZS(binary 8-zero substitution), AMI
and E1 line encoding are high-density bipolar 3(HDB3), AMI
CLOCKING:
free-running --not typical used(neither gets the clock nor
it supplies)
line --service provider is giving the clock
internal ---u r providing the clock (in case u are
connecting to pbx)
show network-clocks ----- command in order to
verify the clocking configuration
Single voice port receiving internal clocking.
Line receives the clock from the PSTN
Configuration :
Router2(config)#controller
T1 1/0
Router2(config-controller)#framing
esf
Router2(config-controller)#linecoding
ami
Router2(config-controller)#clock
source line
Router2(config-controller)#ds0-group
timeslots 1-12 type e&m-wink-start
Internal clocking:
Internal clock supplies the clock to the PBX
Router1(config)#controller
T1 1/0
Router1(config-controller)#framing
crc4
Router1(config-controller)#linecoding
hdb3
Router1(config-controller)#clock
source internal
Router1(config-controller)#ds0-group timeslots 1-15 type
e&m-wink-start
Clock Prioritize
when When two PSTN Lines are connected
network-clock-select 1 e1 0/0
network-clock-select 2 e1 0/1
By default WIC cards are disabled for receving the clock--so
you have to configure which wic card will receive the clocking from PSTN. Go to the global configuration mode and type
the command as below
network-clock-participate
wic 1 (receving clock)
Note: When two or more controllers are
configured for line, one should be designated as the primary clock source; it
drives the other controllers.
Router(config-controlle)#clock source line
primary
Router(config-controlle)#clock source line
secondary 1
Configuration of
T1:
DSO groups:
Dso groups can be deactivated only when the voice port is
deactivated.
1) Defines the T1/E1 channels for compressed voice calls
2) Automatically creates a logical voice port
3) Defines the emulated analog signaling method the router
uses to connect to the PBX or PSTN
T1 CAS Controller
Configuration Example
Enter controller configuration mode.
Router(config)#controller
{t1 | e1} slot/port
Select frame type for T1 or E1 line.
Note: The service provider determines the framing type that
is required for your T1/E1 circuit
T1 Lines:
Router(config-controller)#framing
{sf | esf}
E1 Lines:
Router(config-controller)#framing
{crc4 | no-crc4} [Australia]
Router(config-controller)#clock
source {line [primary | bits] |internal | free-running}
Define the T1 channels for use by compressed voice calls and
the signalling method the router uses to connect to the PBX or CO.
Router(config-controller)#ds0-group
ds0-group-number timeslots
timeslot-list [service
service-type] type {e&m-fgb | e&m-fgd | e&mimmediate-
start | fgd-eana |
fgd-os | fxs-ground-start | fxs-loop-start
| none | r1-itu |
r1-modified | r1-turkey}
The ds0-group command automatically creates a logical voice
port. The resulting logical voice port will be 1/0:1, where 1/0 is the module
and slot
number and :1 is the ds0-group-number argument you assign in
this step.
5)Activate the controller.
Router(config-controller)#no
shutdown
Digital Voice Port
Parameters
After setting up the controller, you can configure voice
port parameters for that digital
voice port. When you specified a ds0-group, the system
automatically created a logical
voice port
Enter voice-port configuration mode.
Router(config)#voice-port
slot/port:ds0-group-number
Router(config-voiceport)#cptone
locale
Activate the voice port.
Router(config-voiceport)#no
shutdow
Configuring T1 CAS
Trunks: Inbound E&M FGD and Outbound FGD EANA
Follow this procedure to configure a T1 CAS digital voice
port with inbound and outbound
ANI:
Step 1. Enter controller configuration mode.
Router(config)#controller
T1 0/0/0
Step 2. Specify the framing format.
Router(config-controller)#framing
esf
Step 3. Specify line coding.
Router(config-controller)#linecode
b8zs
Step 4. Configure one DS0 group to use time slots 1 to 12
and E&M feature group-D.
Router(config-controller)#ds0-group
0 timeslots 1-12 type e&m-fgd
Step 5. Configure another DS0 group to use time slots 13
through 24 and E&M feature group-D EANA.
Router(config-controller)#ds0-group
1 timeslots 13-24 type fgd-eana
Chapter 4: Performing Call Signaling over Digital Voice
Ports 217
Note This creates two voice ports, 0/0/0:0 and 0/0/0:1.
Step 6. An inbound dial peer is configured using the 0/0/0:0
trunk, which supports inbound ANI:
Router(config)#dial-peer
voice 1 pots
Router(config-dialpeer)#incoming
called-number .
Router(config-dialpeer)#port
0/0/0:0
An outbound dial peer is configured using the 0/0/0:1 trunk,
which supports
outbound ANI:
Router(config)#dial-peer voice 90 pots
Router(config-dialpeer)#destination-pattern 9T
Router(config-dialpeer)#port 0/0/0:1
Example T1 CAS
Trunk Configuration Example
Router4(config)#controller
T1 0/0/0
Router4(config-controller)#framing
esf
Router4(config-controller)#linecode
b8zs
Router4(config-controller)#ds0-group
0 timeslots 1-12 type e&m-fgd
Router4(config-controller)#ds0-group
1 timeslots 13-24 type fgd-eana
Router4(config)#dial-peer
voice 1 pots
Router4(config-dialpeer)#incoming
called-number .
Router4(config-dialpeer)#direct-inward-dial
Router4(config)#dial-peer
voice 90 pots
Router4(config-dialpeer)#destination-pattern
9T
Router4(config-dialpeer)#port
0/0/0:1
Example E1 R2
Trunk Configuration
Router5(config)#controller
E1 0/0/0
Router5(config-controller)#ds0-group
0 timeslots 1-31 type r2-digital r2-compelled ani
Router5(config-controller)#cas-custom
0
Router5(config-ctrl-cas)#country
china use-defaults
Router5(config)#dial-peer
voice 90 pots
Router5(config-dialpeer)#destination-pattern
9T
Router5(config-dialpeer)#direct-inward-dial
Router5(config-dialpeer)#port
0/0/0:0
Configuration of
ISDN:
isdn incoming-voice: Configures the interface to send all
incoming calls to the DSP card for processing
interface serial ---Enter voice port configuration mode for
the D channel
Router(config)#isdn
switch-type primary-qsig
Router(config)#controller
t1 0/0
Router(config-controller)#pri-group
timeslots 1-24
Router(config-controller)#interface
serial 0/0:23
Router(config-if)#isdn
incoming-voice voice
Configuring a PRI
Trunk Example
network-clock-participate wic 0 ----The DSP clocking will be
synchronized with the WIC in slot 0.
The line coding for the E1 controller will be linecoding
ami-- default
Router2(config)#interface Serial0/0/0:15---16 line will be
the signalling channel
Performing Call Signaling over Digital Voice Ports 225
Router2(config)#network-clock-participate
wic 0
Router2(config)#isdn
switch-type primary-net5
Router2(config)#controller
e1 0/0/0
Router2(config-controller)#pri-group
timeslots 1-31
Router2(config)#interface
Serial0/0/0:15
Router2(config-if)#isdn
switch-type primary-net5 Router(config-if)# isdn overlapreceiving
Router2(config-if)#isdn incoming-voice voice
Summary of
voice ports:
Router#show controller
T1 1/0/0
Router#show voice dsp
Router#show voice call
summary
show voice port summary
-----command to identify the port numbers of voice interfaces installed
in your router.
show call active voice
---- command to display the contents of the active call table, which
shows all the calls currently connected through the router or concentrator.
show call history voice
------command to display the contents of the call history table.
QSIG:
Example Global QSIG
Support Configuration for BRI
Router(config)#isdn
switch-type basic-qsig
Example Global QSIG Support Configuration for PRI
Router(config)#isdn
switch-type primary-qsig
Specify the card type (T1 or E1) at the specified slot so
the router provides sufficient DSP resources.
Router(config)#card
type t1
Example QSIG over PRI Interface Configuration
Router(config)#controller
t1 0/1
Router(config-controller)#pri-group
timeslots 1-24
Router(config)#interface
serial 0/1:23
Router(config-if)#isdn
switch-type primary-qsig
Router(config-if)#isdn
protocol-emulate user
Example QSIG over
BRI Configuration
Router(config)#interface
bri 1/1
Router(config-if)#isdn
layer1-emulate user
Router(config)#interface
bri 1/1
Router(config-if)#isdn
layer1-emulate network
Router(config-if)#isdn
incoming-voice voice
Router(config-if)#isdn
protocol-emulate user
Router(config)#interface
bri 1/1
Router(config-if)#isdn
protocol-emulate network
Example show isdn status Command
Router#show isdn status
The show isdn status command shows tat Layer 1 =active and
layer 2="MULTIPLE_FRAME_ESTABLISHED" indicates that there is no
problem with layer 1 and 2
If a TEI_UNASSIGNED or AWAITING_ESTABLISHMENT state is
reported, verify the configuration
Global ISDN Switchtype = primary-qsig
ISDN Serial0/1/1:23 interface
dsl 0, interface ISDN Switchtype = primary-qsig
**** Slave side configuration ****
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: 0x00000000
Number of L2 Discards = 0, L2 Session ID = 0
Total Allocated ISDN CCBs = 0
CONFIGURATION OF
T1
You should get the following details from the service
provider
1) Framing
2) Line coding
3) Clock source
Check using below
commands
show controller t1 --->only shows the E1 or
T1 and also the port/slot connected.
show voice port summary
show ip int brief
T1 configuration:
conf t
controller t1 0/1/0 (slot/sub-unit/port)
framing esf
linecode b8zs
clock
source line
no shutdown
CAS Digital
Connections:
T1 ==24DS0 (Digital service level)
1 DSO =64Kbps
dso-group number is between 0 to 23 for T1 and 0 to 30 for
E1.
controller t1 0/1/0
ds0-group 0 timeslots 1-2 type
e&m-immediate-start
ds0-group 10 timeslots 1-4 type fxo-loop-start
(fxo-loop start is mostly used in PSTN
connection )
Note for troubleshooting:
Not enough DSP resources when getting
configurating the t1-->limit the number of slots and try or else add dsp
CCS ISDN
Configuration:
After creating prigroup u will get the serial interfaces
serial0/1/0:0 and will get voice port: voice-card 0/1/0:D port.
conf t
isdn
swith-type primary-qsig
controller
t1 0/1/0
pri-group
timeslots 1-4
When u configure then it u will be getting four serial ports
serial0/1/0:0 serial0/1/0:1 serial 0/1/0:2 serial 0/1/0:3
There is additional port created for signalling and it is
serial0/1/0:23
Configure the
Interface(serial ports)
interface
serial0/1/0:0
The following example for channelized T1 configures the D
channel (hence, all B channels) to answer all incoming voice calls at 56 kbps:
interface serial 0:23
isdn incoming-voice
data 56
NOTE:
for full time slot assignment: pri-group
timeslots 1-24 (T1) pri-group timeslots 1-31 (E1) another e.g pri-group
timeslots 1-10,23
If the controller is of type T1, then the 24th
timeslot is for the control information. ie., Serial x:23 functions as the D-channel.
If the
controller is of type E1, then the 16th timeslot is for the control
information. ie., Serial x:15 functions as the D-channel.
Incoming call:
isdn
incoming-voice voice -------->Configures incoming voice calls
bypass the modems and be handled as a voice call.
isdn incoming-voice modem-->Incoming voice calls are
passed over to the digital modems, where they negotiate the appropriate modem
connection with the far-end modem.
The incoming-voice modem command will allow the router
(Gateway Example:AS5400) to process inbound calls (tones) for both voice and
data. In other words, fax and modem tones as well as voice will be handled
accordingly
ISDN-QSIG:
isdn
switch-type primary-qsig -----> PRI
isdn switch-type basic-qsig ----> BRI
ISDN Status:
show isdn
active----->Shows ISDN calls in progress
show isdn history------>Shows ISDN call
history
show isdn status------->Shows ISDN line
status
show isdn timers-------->Shows ISDN timer
values
debug isdn events------->Displays ISDN
events in real time
debug isdn q921--------->Displays ISDN
Q.921 packets in real time
debug isdn q931 -------->Displays ISDN
Q.931 packets in real time
Transparent CCS
configuration:
This is for Different signalling protocols(for e.g Nortel to
communicate with nortel PBX over the WAN)
For T1 its the 24 time slot used for signalling and E1 16 time slot
conf t
controller
t1 0/1/0
ds0-group
23 timeslot 24 type ext-sig
T1 & E1
T1: Uses TDM to transmit digital data over 24 voice channels
using CAS. There is no need for signalling channel since for CAS signalling is
transferred with data channel itself.
CAS Provides receipt and capture of DNIS(dialed number
identification service) and ANI(automatic number identification)
The most common signalling used with T1 CAS is E&M
signalling
E1: Uses TDM to transmit digital data over 30 voice channels
using either CAS or CCS.
ISDN: Circuit switched telephone network system allowed to
digital transmission of voice and data over ordinary copper wires.
ISDN BRI :128 kb/s ;2 B channels; 1 D channel
T1 PRI :1.5Mbps; 23 B channels ; 1 D channel
PRI NFAS : Multiple ISDN PRI interfaces controlled by single
D channel.
QSIG: Interopeartion of PBX from different vendors.
Configuration
Examples:
The following example shows how to configure a basic
channelized E1 PRI ISDN port adapter. In this example, the controller is
enabled, timeslots are assigned to the PRI group, and the ISDN switch type used
on all ISDN interfaces on the router is a switch for the European community
(primary-net5). The PRI group timeslots of 1, 3, 4, 5, and 7 (the B channels)
are selected to map to timeslot 16 (the D channel), which is recognized by the
system as timeslot 15.
Router#
configure terminal
Router
(config)# isdn switch-type primary-net5
Router
(config)# controller e1 3/1/1
Router
(config-controller)# framing crc4
Router
(config-controller)# linecode hdb3
Router
(config-controller)# pri-group timeslots 1,3-5,7
Router
(config-controller)# exit
Router
(config)# interface serial 3/1/1:30
Router
(config-if)# ip address 1.1.15.1 255.255.255.0
Router
(config-if)# end
The following example shows how to configure a basic
channelized T1 PRI ISDN port adapter. In this example, the controller is
enabled, timeslots are assigned to the PRI group, and the ISDN switch type used
on all ISDN interfaces on the router is for the United States switch
(primary-5ess). The PRI group timeslots of 1, 3, 4, 5, and 7 (the B channels)
are selected to map to timeslot 24 (the D channel), which is recognized by the
system as timeslot 23.
Router#
configure terminal
Router
(config)# isdn switch-type- primary-5ess
Router
(config)# controller t1 3/1/1
Router
(config-controller)# framing esf
Router
(config-controller)# linecode b8zs
Router
(config-controller)# pri-group timeslots 1,3-5,7
Router
(config-controller)# exit
Router
(config)# interface serial 3/1/1:23
Router
(config-if)# ip address 1.1.15.1 255.255.255.0
Router
(config-if)# end
Router#
The following example shows channel group 0 and timeslots 1,
3 through 5, and 7 selected for mapping. The example shows how to configure a
basic channelized E1 port adapter on a Cisco 7200 series router:
Router#
configure terminal
Router
(config)# controller e1 1/1
Router
(config-controller)# clock source line
Router
(config-controller)# framing crc4
Router
(config-controller)# linecode hdb3
Router
(config-controller)# channel-group 0 timeslots 1,3-5,7 ( channel group groups the time slot and
convert to single channel)
Router
(config)# interface serial 1/1:0
Router
(config-if)# ip address 1.1.15.1 255.255.255.0
Router
(config-if)# end
Router#
T1 or E1 Interface
Troubleshooting
To troubleshoot the T1 or E1 interface, perform the
following steps:
SUMMARY STEPS
·
show controller {t1 | e1}
·
Check if the line is down.
·
Check for reported alarms.
·
Check for error events.
·
Check if the interface is T1 or E1 CAS, E1 R2,
or PRI.
Controller Has
Loss of Frame:
Put command show controller {t1 | e1}. If there is any loss
of frame try changing the frame type. If the first framing format does not
work, try the other framing format to see if the alarm clears.
Router# configure terminal
Enter configuration commands, one per line. End with
CNTL/Z.
Router(config)# controller t1 0
Router(config-controlle)# framing esf
For T1 lines, change the line build-out using the
cablelength long or cablelength short command.
Contact your service provider for framing and line coding
settings. Common settings are as follows:
For T1 lines, it is common to use binary 8-zero substitution
(B8ZS) line coding with extended superframe (ESF), and alternate mark inversion
(AMI) line coding with superframe (SF).
For E1 lines, both HDB3 and AMI line coding are available,
but CRC4 framing is most widely used.
E.G OF SHOW
CONTROLLER COMMAND:
show controllers t1 0
T1 0 is up.
Applique type is Channelized T1
Cablelength is long gain36 0db
No alarms detected.
Version info of slot 0: HW: 4, Firmware: 16, PLD Rev: 0
Manufacture Cookie Info:
EEPROM Type 0x0001, EEPROM Version 0x01, Board ID 0x42,
Board Hardware Version 1.32, Item Number 73-2217-5,
Board Revision B16, Serial Number 09356930,
PLD/ISP Version 0.0, Manufacture Date 18-Jun-1998.
Framing is ESF, Line Code is B8ZS, Clock Source is Line
Primary.
Data in current interval (8 seconds elapsed):
0 Line Code Violations, 0 Path Code Violations
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded
Mins
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0
Unavail Secs
The main
items to look at in the above output is
1)The status of the line
2)Alarms
Linecode and Pathcode violations
3) Slip Secs: If
timing differs then voice quality,noice problems in the call arises
In most cases, you can check for clock slips on the E1 or T1
interface in order to confirm the problem. Issue the show controller {e1 | t1}
command for confirmation:
Router# show
controller e1 0/0
E1 0/0 is up.
Applique type is
Channelized E1 - balanced
No alarms
detected.
alarm-trigger is
not set
Version info
Firmware: 20020812, FPGA: 11
Framing is CRC4,
Line Code is HDB3, Clock Source is Line.
Data in current
interval (97 seconds elapsed):
0 Line Code
Violations, 0 Path Code Violations
4 Slip Secs,
0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
4 Errored
Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
A common message you will see in the alarm field is
"receiver has loss of frame." ---->check framing is correct
Another message you might receive is "receiver is
getting AIS." ----->This means the receiver is getting an alarm indication
signal (blue alarm)
This is typically seen when the far-end CSU has lost its
terminal side equipment. The "receiver has remote alarm" indicates
the presence of a yellow alarm. This means the downstream CSU is in a
loss-of-frame or loss-of-signal state. Therefore, the remote CSU has a red
alarm.
The "transmitter is sending remote alarm"
indicates that the local CSU has detected either a loss-of-frame or
loss-of-signal condition
Always verify framing and T1 signal when troubleshooting
this problem.
Whenever you are troubleshooting a T1, always verify that
both-sides of the circuit are running clean. It is possible that only one side
of the T1 is seeing errors. Remember, that the T1 is going only between you and
the provider. Always contact the provider to make sure they aren't seeing
errors on their side of the circuit.
Troubleshooting the ISDN connection:
show isdn
status
E.g output of the command:
ISDN BRI3/0 interface
dsl 16,
interface ISDN Switchtype = basic-ni
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 64, Ces
= 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
TEI = 73, Ces
= 2, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
TEI 64, ces =
1, state = 5(init)
spid1
configured, spid1 sent, spid1 valid
Endpoint
ID Info: epsf = 0, usid = 0, tid = 1
TEI 73, ces =
2, state = 5(init)
spid2
configured, spid2 sent, spid2 valid
Endpoint
ID Info: epsf = 0, usid = 1, tid = 1
Layer 3 Status:
0 Active Layer
3 Call(s)
Active dsl 16 CCBs
= 0
The Free Channel
Mask: 0x80000003
Total Allocated
ISDN CCBs = 0
To determine whether
everything is copacetic, you should look for three main things in this output:
Layer 1 Status should say Active.
Layer 2 Status should say MULTIPLE_FRAME_ESTABLISHED.
Under Layer 2, spid1 and spid2 should both say
configured and valid.
If Layer 1 is down
Calling the carrier and opening a ticket for a Layer1 Down
status, let's keep investigating. On the interface, try using the clear isdn
interface bri0/0 command and the no shutdown command.
REFERENCE WEBPAGES:
http://ccie-security.blogspot.com/2008/10/t1-wierdness.html
http://docwiki.cisco.com/wiki/Cisco_IOS_Voice_Troubleshooting_and_Monitoring_--_T1_or_E1_Interface_Troubleshooting#Troubleshooting_T1_and_E1_Layer_1_Problems
