Serial0 with T1 setup 1

[bubarooni]

I am getting ready to switch from a wic-1enet using broadband to a wic-1dsu-t1 using a full AT&T T1 at one of my sites and am not to sure what to do with some of the info I have. The current router is used for a vpn back to my main office and internet access at that site. I am configuring a spare router to take there and make the switch.

My AT&T TID sheet lists:

Line Coding / Framing: ESF/B8ZS
Serial Encapsulation: PPP
Timing: Net/Line
Port Base Rate (per channel): 64K
Channels: 1-24

On the router I have my wic-1dsu-t1 configured as such:

interface Serial0
 description connected to the internet
 ip address 12.116.234.150 255.255.255.252
 ip access-group 16 in
 ip nat outside
 no ip mroute-cache
 half-duplex
 no keepalive
 no fair-queue
 crypto map towash

Do I need to add that 'stuff' about the line coding, etc in there someplace?

Thanks In Advance

 

[JOAMON]

Serial 0 should no have a duplex command. You will need to add encapsulation ppp onto it as well. The line coding indicated is the default for a T1 WIC.

 

[bubarooni]

geez. i'm a dork!

i put a real ip in there!

thanks for your help though!

maybe i can get them to delete it.

 

[JOAMON]

with what you posted I would not worry about it so long as http server is not on and you have secured the VTY lines for local access only.

 

[bubarooni]

I keep seeing these lines in configs for t1's on these serial interfaces:

service-module t1 timeslots 1-24
service-module t1 remote-alarm-enable

Should I have those too?

 

[JOAMON]

24 timeslots are the default...only need to do this if less than full T1.
You can enable remote alarm if you wish...info from Cisco:

service-module t1 remote-alarm-enable
To generate remote alarms (yellow alarms) at the local CSU/DSU or detect remote alarms sent from the remote CSU/DSU, use the service-module t1 remote-alarm-enable interface configuration command. To disable remote alarms, use the no form of this command.

service-module t1 remote-alarm-enable
no service-module t1 remote-alarm-enable

 

[rainman]

You should find out what type of router you are connecting to, so you can determine the proper encapsulation to run. Cisco uses "HDLC" as default, and it's usually best to use "PPP" when doing Cisco > non-cisco. If you are connecting to AT&T more than likely you are getting a T1 off of one of their Cisco routers so the default HDLC encapsulation will work.

interface Serial0
description connected to the internet
ip address x.x.x.x y y y y
ip access-group 16 in
ip nat outside
no ip mroute-cache
!
! I dont know why half-duplex is here. Serial lines
! do not follow ethernet duplex standard. Mistype?
!
half-duplex
no keepalive
no fair-queue
crypto map towash
!
! T1 configuration on Serial0 link
! Note: the below commands are all DEFAULTS
! so as long as u are running a full T1 @ 24 channels
! you do not need any of these. The only command
! that is NOT a default is the "remte-alarm-enable"
! which was explained above by JOAMON regarding what
! remote-alarm-enable does.
!
service-module t1 timeslots 1-24
service-module t1 clock source line
service-module t1 remote-alarm-enable


Also, the above are just factors regarding your Serial0 interface. If you are currently using a WIC1ETH and cutting over to Serial0 then what about routing?

Do you have a static route running right now to send all your traffic out the Ethernet0 interface? If so you will need to change that to send traffic out your new Serial0 interface:

config term
!
no ip route 0.0.0.0 0.0.0.0 Ethernet0
ip route 0.0.0.0 0.0.0.0 Serial0
!
end


Hope this helps... T1's are easy especially since you are cutting over from an interface already on your router.


-Rainman

 

[bubarooni]

JOAMON cleared up most my misconceptions earlier.

I do have one last question though.

My config is running right now with:

ip route 0.0.0.0 0.0.0.0 xxx.xxx.xxx.xxx

should if replace that with:

ip route 0.0.0.0 0.0.0.0 Serial0

Thanks!