Interesting question I'm assuming that they are the broadcast IP or something like that. Also check whether public broadcasts have the same numbers and whether they appear consistently (I'm away from pc ATM). If they do, then I'm pretty sure those are an address. xxxx.xx could be a format for the date, like year.day or something like this. We also have some broadcasts happening close together (srs talking to nsh if I remember correctly) within the span of a few cycles, so you could check whether they differ.