CCO doc error (?): modem on console

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On CCO there is a doc for connecting a USR modem to the console port of a router. In reading this, there seems to be an obvious error in steps 2 and 3:

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:On CCO there is a doc for connecting a USR modem to the console port of a :router. In reading this, there seems to be an obvious error in steps 2 and 3:

:2

:On the modem, restore the factory defaults by turning off the modem, setting :DIP switch seven down and turning on the modem. After this, turn the modem off :again. Reference the Miscellaneous section of this document for information :about DIP switch settings

:3

:Set DIP switches one, three and eight down and all others up. Turn the modem :back on. Reference the Miscellaneous section of this document for information :about DIP switch settings

:Step 3 can be read to say that dip 7 from step 2 should be turned back up. If :you do this, you totally invalidate step 2's purpose. Shouldnt dip 7 be left :down during steps 3 and beyond up until the init string is saved ?

Not necessarily.

The problem with that document is that it doesn't say which model of USR modem is being used. According to the USR documentation, there are different DIP configurations on various models. Switch 7 down has completely different meanings in the various models. We can deduce from the "one, three and eight" that the document is not talking about newer USR external models such as the V.Everything, which has 10 DIP switches. It could be talking about older USR external serial modems, or about USR external USB modems.

If you refer to the meaning that Cisco documents in the Miscellaneous section for switch 7, you will see that it indicates, "Power-on and ATZ Reset Software Defaults". That's a slightly different meaning than is documented in some of USR's documentation, which indicates that switch 7 up forces &F0 (no flow control) to be loaded from ROM.

If you compare the DIP switches mentioned and the exact phrasing used, you will find that likely Cisco was looking at the documents for the Sportster modems connected to PCs (an additional DIP needs to be flipped for Macintosh.) The Sportster document uses the Cisco phrasing for Switch 7 down, but indicates that switch 7 up loads &F0 from ROM.

It's not entirely clear that Cisco is wrong with respect to the Sportster, but your interpretation is reasonable, and it would be -safer- to leave the switch up until you had saved the configuration.

My interpretation would be that it tells us that Cisco was looking at the documentation for some particular model (e.g., Sportster) that had the properties described; other models may have handled matters differently. USR *did* change the meaning of the DIP switches over time with the external serial modems, so the USR generic description *is* incomplete... and the Cisco document is even more incomplete. The generic USR description might hold for the Sporster 33K and up though... but not, for example, to their 1200 bps modem.

Should you send that link out to customers? Probably not without caviats. Even if Cisco is right about some particular model, there are other models with other DIP configurations.

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Walter Roberson

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