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New Member

as5200 dialup connects only at 9600bps

trying to configure an AS5248 with 56K modems for dial-in, I've got everything working but I can connect only at 9600 baud.

I don't know whether its a modem issue or a T1 issue.

with no control over the DTE/DCE, I can dial-up, connect, register my computer on the network.

when I try to control the DTE/DCE with the below commandS


rxspeed, txspeed commands, setting to 57600

speed command, setting to 57600

I then use

debug ppp authen

debug ppp negot

terminal monitor

with the line configuration shown below I connect and see authentication and negotiation debug information. When I try autobaud, speed, or rx/txspeed commands I see no debug information even if I set speed to 9600.

here are the T1 line configurations...

controller T1 0

framing esf

clock source line primary

linecode b8zs

cas-group 0 timeslots 1-24 type e&m-fgb


controller T1 1

framing esf

clock source line secondary

linecode b8zs

cas-group 1 timeslots 1-24 type e&m-fgb

Here are the modem configurations.

line 1 48

autoselect during-login

autoselect ppp

modem InOut

modem autoconfigure type usr_sportster

transport input all

thanks for any input.

New Member

Re: as5200 dialup connects only at 9600bps

Hi, I'd suggest checking the modem portware version being used with "show modem version". I think you have Microcom 56k modems, and if so I'd at least consider changing the portware unless you already are using the newest version which is 5.3.30. It's really easy to update the modem firmware which is available with update instructions at the Software Center with your CCO login.

Regardless of the portware issue I'd test access with a couple simple config changes:

conf t

line 1 48

flowcontrol hardware

modem autoconfigure type mica

default speed


'flowcontrol hardware' will let the modem to modem link figure out how to best deal with the data stream over the telco link.

The 'autoconfigure' command change will simply send &F to the Microcom modems when they are initialized which should be all they really need to see. You can compare that init string to the usr-sportster modemcap with "show modemcap usr_sportster". By the way, "show modemcap" will list the names of modem init strings the IOS has built-in and also any you have manually configured. Then "show modemcap " will show the contents of any particular defined (built-in or manual) modemcap.

Not being at a 5200 I am not certain you will have the "default speed" command, but you should not need to specify a speed at all, and "default speed" will set rx and tx speeds to their defaults if the command is available. Sometimes "locking" the modem speed is needed, but not generally.

The "autoconfigure" command actually will check at all speeds starting with 115200 trying to find a modem. It will then continue communications with the modem at the highest speed that works. This should not be something you need to configure around. You can watch output from "debug modem" and "debug confmodem" when you clear a modem line with "clear line ", for example, "clear line 10", then confirm it. You will see the "autoconfigure" command at work locating the modem and sending it the initialization string.

Be sure the modem is well-seated and that your cabling is good all the way to telco demarc... that's Layer 1, of course.

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