Re: dce-terminal-timing-enable

ujamc · ‎07-21-2004

1. i tried to enable dce-terminal-timing-enable on a serial interface on a port of a NM-16A/S network module on a Cisco 3745 router and the error message not allowed on DTE interface. What can I do to remedy this, I have CAB-SS-449MT attached to DCE.

2. Same with a Cisco 1600 router using its WIC-1T serial interface and CAB-530MT cable.

3. Trying to enable Network-clock-participate on a slot with NM-4T network module reported an error indicating that it is not support. what is the remedy to this.

Regards,

uche

stephenshaw · ‎07-22-2004

Hi Uche,

Based on the cables you indicate, the router is expecting to be receiving clocking.

Cisco routers do not allow DCE commands for interfaces connected to a DTE cable. You must change the cable to DCE types and then the router is responsible for providing the clocking.

Regards,

Steve

smif101 · ‎07-22-2004

Why do you want to use the clock from the cisco router and not from the service provider. The cisco will only be able to provide stratum 3 at best while the ISP will be at stratum 2 or higher.

ujamc · ‎07-22-2004

It is really for a vsat network and clocking issues are causing packets to be dropped and timeout results.

The dce cables come with female connectors so would not fit in would I use a gender changer to overcome this?

The central hub router has a single 1.26Mb TX serial port and 16 64Kbps and 2 128Kbps RX ports from different remotes.

Included is the central router config. The remotes are in a star topology around the hub router.

syshub#sh star

Using 5201 out of 155640 bytes

!

version 12.3

service config

service timestamps debug datetime msec

service timestamps log datetime msec

no service password-encryption

!

hostname syshub

!

boot system flash:c3745-ipbase-mz.123-2.t6.bin

enable secret xxxxxxxxx

enable password xxxxxxxxx

!

network-clock-participate slot 2

network-clock-participate slot 3

no aaa new-model

ip subnet-zero

!

no ftp-server write-enable

!

interface FastEthernet0/0

ip address 192.168.100.1 255.255.255.0

speed 100

full-duplex

no cdp enable

no mop enabled

!

interface FastEthernet0/1

no ip address

shutdown

duplex auto

speed auto

no cdp enable

!

interface Serial1/0

bandwidth 1260

ip address 10.1.0.2 255.255.255.0

no ip split-horizon

serial restart-delay 0

!

interface Serial2/0

description uhslonipanu receive

ip address 10.10.0.2 255.255.255.0

!

interface Serial2/1

description uhsl balogun receive

transmit-interface Serial1/0

bandwidth 64

ip address 10.11.0.2 255.255.255.0

!

interface Serial2/2

description uhsl ikoyi receive

transmit-interface Serial1/0

bandwidth 64

ip address 10.12.0.2 255.255.255.0

!

interface Serial2/3

description uhsl kano receive

transmit-interface Serial1/0

bandwidth 64

ip address 10.13.0.2 255.255.255.0

.

interface Serial2/15

description uhsl aba receive

transmit-interface Serial1/0

bandwidth 64

ip address 10.25.0.2 255.255.255.0

!

interface Serial3/0

description uhsl uyo receive

transmit-interface Serial1/0

bandwidth 64

ip address 10.26.0.2 255.255.255.0

!

interface Serial3/1

description uhsl benin receive

transmit-interface Serial1/0

bandwidth 64

ip address 10.27.0.2 255.255.255.0

!

interface Serial3/2

no ip address

shutdown

.

interface Serial3/15

no ip address

shutdown

!

router ospf 15

log-adjacency-changes

network 10.0.0.0 0.255.255.255 area 15

network 172.16.0.0 0.0.255.255 area 15

ip classless

ip route 172.16.7.0 255.255.255.0 10.1.0.10 3

ip route 172.16.10.0 255.255.255.0 10.1.0.10 3

ip route 172.16.11.0 255.255.255.0 10.1.0.11 2

ip route 172.16.12.0 255.255.255.0 10.1.0.12 2

ip route 172.16.13.0 255.255.255.0 10.1.0.13 2

ip route 172.16.14.0 255.255.255.0 10.1.0.14 2

ip route 172.16.15.0 255.255.255.0 10.1.0.15 2

ip route 172.16.16.0 255.255.255.0 10.1.0.16 2

ip route 172.16.17.0 255.255.255.0 10.1.0.17 2

ip route 172.16.18.0 255.255.255.0 10.1.0.18 2

ip route 172.16.19.0 255.255.255.0 10.1.0.19 2

ip route 172.16.20.0 255.255.255.0 10.1.0.20 2

ip route 172.16.21.0 255.255.255.0 10.1.0.21 2

ip route 172.16.22.0 255.255.255.0 10.1.0.22 2

ip route 172.16.23.0 255.255.255.0 10.1.0.23 2

ip route 172.16.24.0 255.255.255.0 10.1.0.24 2

ip route 172.16.25.0 255.255.255.0 10.1.0.25 2

ip route 172.16.26.0 255.255.255.0 10.1.0.26 2

ip route 172.16.27.0 255.255.255.0 10.1.0.27 2

ip route 172.16.100.0 255.255.255.0 10.1.0.10 2

!

ip http server

!

line con 0

exec-timeout 0 0

line aux 0

line vty 0 4

password xxxx

login

end

Please could you help me with this and if we need to change any cables or config.

Thanks in advance.

Uche

smif101 · ‎07-22-2004

The problem would get worse if you went to DCE on the router. Unless you have the DCE settings for your SATCOM set to DCE TT you will still get problems. Have you put up a firebird test set to ensure you have a good circuit end to end yet? If it is not good then troubleshooting will have to be done on the circuit, be it weather related problems, poor reception or what have you. The router should always pull clock from the DCE. Is this a brand new circuit or existing? If it has been around for a while, it will be a cableing or equipment issue and that is what the test sets will prove. What is the reliablity of the interface that is in question?

ujamc · ‎07-22-2004

This is a newly commissioned network which is yet to work properly. And the test values seem okay.

I can telnet into remote sites but the traffic is not stable as the link keeps breaking off.

and ping test comes and goes like replies for 8-10 pings then host unreachable for the next ten pings and back again.

smif101 · ‎07-22-2004

You can't determine a clocking issue because you are getting errors. That takes test equipment and an o-scope to really determine if your Data and Clock are floating freely which in turn would create a consistent data problem. I am a little confused about your setup though. You state the 64K circuits are receive, and your 1260 serial interface is transmit. Do you have separate freqs setup for each remote site to link up to one of your serial links, for instance you have like 8 separate sat modems? And what is the configuration of a typical remote site? Are you recieving input and crc errors on all of your serial links, what is the load and reliability on the serial links in question? You might be having issues with bandwidth because of OSPF if you have flapping routes.

smif101 · ‎07-22-2004

By the way I have never worked with VSAT before, mostly it is dedicated links over 1Mbs. I hope what you are using isn't a shared hub network.

peter.payne · ‎07-25-2004

Maybe I'm way off base again, but are you trying to do a back-to-back solution? Anyway, that's what I've tried and on one of the routers I did this:

interface Serial0/0

bandwidth 500

no ip address

encapsulation frame-relay IETF

clockrate 500000

dce-terminal-timing-enable

frame-relay traffic-shaping

frame-relay lmi-type cisco

frame-relay intf-type dce

frame-relay lmi-n392dce 3

frame-relay lmi-n393dce 3

The important line being:

frame-relay intf-type dce