~ firstname.lastname@example.org (Christoph Gartmann) writes: ~ >does an old router 2503I with an ISDN-BRI-interface support the dial-in via an ~ >analog modem over the BRI interface? It has an "incoming-voice modem" command. ~ >But I am not quite sure whether this is really possibly. Any hints? ~ ~ I couldn't answer you totally authoritatively, but I would suspect not.
I *can* answer this authoritatively, and the answer is definitely not.
~ An ~ analog modem is going to require a DSP at some point. Ie. the 36xx/37xx/38xx ~ solution with NM-1CT1 card doing analog modems still requires a NM- ~ DSP card in order to terminate the analog calls coming in over ISDN. ~ ~ The 2503 is long before cisco dabbled in modems or DSPs.
~ You'd be able to take in ISDN calls to the box or place outgoing ISDN calls, ~ but not voice or modem over the B channel of that ISDN connection.
You could make this work with the 2503 something like this, maybe:
---U loop---[NT1]--S/T---------------------------------[[BRI0] 2503 [aux]] \\ / \\_[analog TA]_[analog modem]__________________/