<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">1/ in general (personal view), in systems of non-trivial size, the wish of maintaining “<i class="">accurate timing</i>” could be difficult and costly, especially if one also adds considerations of supporting ad hoc mobile / high dynamics into the protocol design.<div class=""><br class=""></div><div class="">2/ the “freshness period” carried in data packets is not designed for “<i class="">accurate</i> cumulative cache time”. </div><div class="">As I understand, it’s a rough tuning knob for the data producer to guard against high request rate for the same data, “dont ask me for XX again with 'freshness period’" </div><div class="">One could use it as a consideration factor in cache management.</div><div class=""><br class=""></div><div class="">3/ as an old person in networking, I’d just like to share with young generations the observation that a few decades back there were lots lots efforts that went to router packet scheduling for “real time apps”, like voice calls and conferencing — today Skype and zoom are commonplaces, just without using those early days solutions.</div><div class=""><br class=""><blockquote type="cite" class="">On Feb 3, 2021, at 7:19 AM, Samar Alduayji <<a href="mailto:samarduayji@gmail.com" class="">samarduayji@gmail.com</a>> wrote:<br class=""><br class="">Thanks for replying Lixia, really appreciate it.<br class=""><br class="">1/ wonder why you are interested in carrying (x-y seconds) in the packet? (Playing with cache management?)<br class=""><br class=""> The idea is to keep trake of the accurate remaining data lifetime. <br class="">So how would a node or a consumer knows if a packet is expired or became stale without considering how much it stayed in the previous CS? How the freshness period will be decreased over the caching and transmission time? Is there any other indicator for that? <br class=""><br class="">Regards,<br class="">Samar <br class=""><br class=""><br class="">On Wed, 3 Feb 2021, 5:15 pm Lixia Zhang, <<a href="mailto:lixia@cs.ucla.edu" class="">lixia@cs.ucla.edu</a>> wrote:<br class=""><br class="">> On Feb 3, 2021, at 2:04 AM, Samar Alduayji via ndnSIM <ndnsim@lists.cs.ucla.edu> wrote:<br class="">> <br class="">> Dear All,<br class="">> <br class="">> I just have a question regarding handling the freshness value of data packet when it is sent from one node to another. <br class="">> i.e. when a data packet is cached in node A with freshness value ( ttl) of x seconds, then after y seconds the data is retrieved to be send to another node B. Will the freshness value stay x seconds or there is a process that it implemented within the ndnsim to change it to x-y seconds? <br class=""><br class="">ndnSIM follows NDN design.<br class="">By design the whole data packet, including the freshness period, is signed by the original producer (cannot be changed by other parties).<br class=""><br class="">1/ wonder why you are interested in carrying (x-y seconds) in the packet? (Playing with cache management?)<br class=""><br class="">2/ to experiment, someone suggested earlier the idea of attaching such a value to the data packet (e.g. by NDNLP), I dont think ndnSIM itself does it.<br class=""><br class="">> If there is such a handling function that is already implemented can you please point it out for me? <br class="">> <br class="">> Kind Regards <br class="">> _______________________________________________<br class="">> ndnSIM mailing list<br class="">> ndnSIM@lists.cs.ucla.edu<br class="">> http://www.lists.cs.ucla.edu/mailman/listinfo/ndnsim<br class=""><br class=""></blockquote><br class=""></div></body></html>