I (finally) got some test equipment for ISDN / SS7 / GSM development, first thing i managed to buy at an auction on eBay is a Siemens K1103 Protocol Analyzer (monitoring only). The newest “member of the family” is a HP 37900D Protocol Analyzer / Simulator. Both are PRI only so the next thing i’ll have to get is at least one PRI card.
I’d have preferred to get a HFC based one (mISDN is part of the kernel now…), but the prices of those are really insane, i could easily get a double port PCIe card from Digium / OpenVOX / whatever for the amount a single Port HFC-E card would usually cost (~500 – 700Eur)…
I’ll probably just buy some cheap chinese TE110P clones on eBay (cheap as in _really_ cheap, 85Eur + shipping) and hope they’re working reliably enough to use them. 400 – 700Eur is just too much for what is still a hobby (and no, asking vendors to get stuff for free/discounted for OSS development isn’t what i’m going to do).
UPDATE: Minimum record for HFC-E1 cards: 350Eur (+ shipping), an italian online shop.