A delayed zip tone is a software issue, not a hardware issue.
Tones can come from many board types depending on you hardware platform, cabinets, media-gateways.
Adjusting for a delayed ziptone can be done on the form.
tn2182, tn2312, tn744E, media-gateways have built-in tone generation.
A great teacher, does not provide answers, but methods to teach others "How and where to find the answers"
bsh
37 years Bell, AT&T, Lucent, Avaya
Tier 3 for 27 years and counting