06-06-2007 12:26 AM
Hi All,
I am in Nairobi Kenya. Here we use ISDN Basic-net3 and my problem is that most of the telco switches here deactivate Layer 1 when there is no active call.
When I try to initiate a call by using the ISDN test call command I get an error to the effect that B channel is not available.
The only way I can initiate a call is I first call the line then and then disconnect. Then I have about 5 seconds to make a test call and pings are successful. How do I make the router initiate a call when layer 1 is deactivated.
the debug isdn q921 out has nothing till a call comes in.
I also understatnd that European ISDN switches deactivate Layer 1 when there no active call. I dont have a problem with one of the switches, coz it does not bring down the line when there is no active call.
Thakx in advance
Martin
06-06-2007 02:01 AM
Hello,
saying "deactivating layer 1" or "bringing down the line" when there is no active call, is absolutely the same thing.
As you said, this is normal behavior for european switches and I think for the switch you have there too.
This said, the router should be able to reactivate the line to place an outgoing call, without needing an incoming call first.
Please send: router model and exact IOS version, router configuration.
06-06-2007 02:32 AM
Thanks for the quick response.
It is a cisco 1760
The IOS is c1700-sv3y-mz.122-15.T5.bin
When I try to make a test call the show isdn status initially indicates that the router is trying to activate layer 1 then after 5 seconds it indicates that it is deactivated.
I have not yet configured DDR as indicated in the config file
Building configuration...
Current configuration : 3054 bytes
!
! Last configuration change at 00:38:54 UTC Mon Aug 9 1993
! NVRAM config last updated at 00:36:54 UTC Mon Aug 9 1993
!
version 12.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Gill-House
!
logging queue-limit 100
enable secret xxx
!
ip subnet-zero
!
!
no ip domain lookup
!
!
isdn switch-type basic-net3
!
!
!
!
!
!
!
!
no voice hpi capture buffer
no voice hpi capture destination
!
!
!
!
class-map match-all voice-traffic
match ip rtp 16384 16383
!
!
policy-map voice
class voice-traffic
priority 24
class class-default
fair-queue
!
gw-accounting syslog
!
!
interface Loopback0
description Loopback interface for VoIP Dial-peers
ip address 128.1.x.x.255.255.255
!
interface Multilink1
bandwidth 6
ip address 128.1.x.x.255.255.252
ip tcp header-compression iphc-format
ppp multilink
ppp multilink fragment-delay 20
ppp multilink interleave
multilink-group 1
ip rtp header-compression iphc-format
!
interface FastEthernet0/0
description Gill-House LAN
ip address 128.1.x.x.255.255.0
speed auto
!
interface Serial0/0
description Link to Head Office
bandwidth 64
no ip address
encapsulation ppp
no fair-queue
ppp multilink
multilink-group 1
!
interface BRI1/0
ip address 10.10.1.2 255.255.255.0
encapsulation ppp
isdn switch-type basic-net3
isdn point-to-point-setup
keepalive 20
!
router eigrp 100
passive-interface FastEthernet0/0
passive-interface Loopback0
network 128.1.0.0
no auto-summary
no eigrp log-neighbor-changes
!
ip classless
no ip http server
!
!
!
logging source-interface Loopback0
logging 128.1.1.179
!
call rsvp-sync
!
voice-port 2/0
cptone GB
ring frequency 50
!
voice-port 2/1
cptone GB
ring frequency 50
!
dial-peer cor custom
!
!
!
dial-peer voice 2 pots
destination-pattern 101
port 2/0
!
dial-peer voice 51 voip
destination-pattern 100
session target ipv4:128.1.0.254
ip qos dscp cs5 signaling
!
dial-peer voice 55 voip
destination-pattern 120
session target ipv4:128.1.31.254
ip qos dscp cs5 signaling
!
dial-peer voice 52 voip
destination-pattern 102
session target ipv4:128.1.91.254
ip qos dscp cs5 signaling
!
dial-peer voice 53 voip
destination-pattern 103
session target ipv4:128.1.121.254
ip qos dscp cs5 signaling
!
dial-peer voice 54 voip
destination-pattern 110
session target ipv4:128.1.21.254
ip qos dscp cs5 signaling
!
dial-peer voice 56 voip
destination-pattern 130
session target ipv4:128.1.41.254
ip qos dscp cs5 signaling
!
dial-peer voice 57 voip
destination-pattern 140
session target ipv4:128.1.111.254
ip qos dscp cs5 signaling
!
dial-peer voice 58 voip
destination-pattern 150
session target ipv4:128.1.61.254
ip qos dscp cs5 signaling
!
dial-peer voice 59 voip
destination-pattern 160
session target ipv4:128.1.71.254
ip qos dscp cs5 signaling
!
!
line con 0
logging synchronous
line aux 0
line vty 0 4
password housing
login
!
ntp clock-period 17208074
ntp server 128.1.1.211
ntp server 128.1.0.254
end
Gill-House#
06-06-2007 12:44 PM
Hi,
Your ISDN configuration appears incomplete.
Specifically, it misses the required "dialer string" or "dialer map" necessary to place a call.
Please see an example of configuration at:
http://cisco.com/en/US/tech/tk801/tk379/technologies_configuration_example09186a0080093d4a.shtml
The above document also introduce a command "isdn tei-negotiation preserve" that is useful when switches brings down layer 1 on inactivity.
If still doesn't work, I suggest you upgrade to 12.2(46)
Hope this helps, please rate post if it does!
06-07-2007 01:58 AM
I am using the "isdn test call" command to make a call. The "debug isdn error" output indicates that B- channel could not be found when i try to place a call . At another site the 2801 router works fine. I also tried the "isdn tei-negotiation preserve" and still cannot make a call with the 1760 router.
I will upgrade the IOS but mean while I will try with another type of router first.
I will get back to you.
Thanks
06-07-2007 03:17 AM
Hi,
Be aware that different IOS versions may behave differently with regard to "isdn test call". Why not testing the circuit with a regular configuration, and then ping to ip ?
I suggest you upgrade the IOS first before switching router. Unfortunately IOS has an history of bugs in ISDN so chances are that something has been fixed.
06-27-2007 02:18 PM
Hi,
I have seen some ISDN switches which has a power saving option.it shuts down the port keeps in a standby mode unless a call comes in. which will re enable the ports and bring it back up. PLease check with the SP to get the model and what is the configuration of their ISDN Switch.
Thanks and Regards,
Srinath.M
Cable&Wireless
06-28-2007 02:07 AM
The SP has 3 types of switches. The switches that are giving me problems are known as Linear UT. They have been configured to shut dsown the port when there is no active call. The NEAX switch is working fine. Someone told me to use the BRI-S/T and use an external NT1. Currently I am using BRI-U cards. What do you think.
06-28-2007 07:23 AM
Hi,
When you use a external NT1 you will find your L1 as active but L2 deactivated. Only when a call comes it will be active.
Thanks and Regards,
Srinath.M
Cable&Wireless
06-28-2007 08:07 AM
Would definitely try with BRI-S/T and external NT.
BRI-U was designed for the US market where there is no deactivation on inactivity.
06-28-2007 07:53 AM
Hi,
Please try this configuration
!
interface BRI0
no ip address
encapsulation ppp
dialer rotary-group 1
dialer-group 1
isdn switch-type basic-net3
isdn tei-negotiation preserve
no cdp enable
ppp authentication chap
!
Please find the following link as well.
http://www.cisco.com/warp/public/793/access_dial/tei_negotiation.html
I hope it helps.
Thanks and Regards,
Srinath.M
Cable&Wireless
06-28-2007 10:05 AM
Hi Martin,
From your post, I guess you are only concerned about the ISDN Test Call? Correct?
Also, please give us the outputs from:-
sh isdn status
sh int bri 0/0
sh ver
06-28-2007 11:01 PM
Hi,
Please try the same with this command.
isdn tei-negotiation preserve
Thanks and Regards,
Srinath.M
Cable&Wireless
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