sethcohn%alchemy.uucp@theory.tn.cornell.edu (seth cohn) (01/30/91)
I recently had a second phone installed for a BBS system. The operator gave me a choice of: 1) a testable network interface 2) a NONtestable network interface What's the difference? (Besides about $5 :) ) Seth Cohn
drmath@iuvax.cs.indiana.edu (Doctor Math) (02/01/91)
sethcohn%alchemy.uucp@theory.tn.cornell.edu (seth cohn) writes: > I recently had a second phone installed for a BBS system. The > operator gave me a choice of: > 1) a testable network interface > 2) a NONtestable network interface > What's the difference? (Besides about $5 :) ) The "testable" network interface probably has a modular jack wired inside of it such that all the wiring in your house (past demarc) can be unplugged, allowing the customer to plug in an ordinary phone and see if the inside wiring is at fault before calling repair. A less likely possibility is that it contains a chip that the telco can "see" from the CO, also to determine where any problem lies. I say "less likely" because (at least here) they've stopped using these chips; apparently they register about a ringer and a half and this was causing problems (installer told me this as I watched him yank out all six of the little buggers).
lairdb@crash.cts.com (Laird P. Broadfield) (02/16/91)
>On 29-JAN-91, Seth Cohn wrote: >> I recently had a second phone installed for a BBS system. The operator gave >> me a choice of: >> 1) a testable network interface >> 2) a NONtestable network interface >> What's the difference? (Besides about $5 :) ) This is probably an SNI with a built in MTU. (Do you feel informed now?) SNI: Standard Network Intervace (residential semi-equivalent of a 'demarc') MTU: Maintenance Test Unit The MTU is a gadget that has several capabilities depending on what model is installed. The minimum (that I've seen) is that when presented with a specific tone from the CO side, it will disconnect the premises side, allowing the guy on the test desk to quickly determine if the problem is in your equip. or theirs. Many also will send back a test tone, or a series of test tones and quiet time, allowing the test-dude to measure line quality, etc. Some also include the ability to disconnect your equipment automatically in the event of a short on your side (these can be set for "latching" or "non-latching", meaning does the telco have to visit in order to reset it (and charge you $$)). No idea why they would offer you an option; the devices certainly should be cost-effective for them to install everywhere, especially since they could just have charged you for it and not offered the option. Laird P. Broadfield UUCP: {akgua, sdcsvax, nosc}!crash!lairdb INET: lairdb@crash.cts.com