Re: [mpls] How many flags could be set in an NAI Flag field
Tony Li <tony.li@tony.li> Wed, 27 April 2022 15:15 UTC
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From: Tony Li <tony.li@tony.li>
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To: Loa Andersson <loa@pi.nu>
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Subject: Re: [mpls] How many flags could be set in an NAI Flag field
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Hi Loa, > I've been thinking about "how many flags" will be set? Predicting the future is easier once you’ve lived it. :-) > Assume that we have the possibility to set about 20 Network Action Indicators in a flag field carried in a new bSPL (more than what can be carried in the repurposed TTL and TC fields. In fact, depending on the encoding, a solution could carry many more NAI. > I assume the most packet will not carry the bSPL. > > Of those that does, most will have just one flag. This is not clear to me. It’s pretty clear that ECMP is popular and is likely to become more popular, based on the trends that we see within data centers. The claims of 5G network slicing seem dubious to me, but on the off chance that I’m wrong, we could easily end up carrying EL and GISS frequently. And this says nothing about flags that are still to be proposed. My gut says that we could easily see a day where slicing is almost ubiquitous and ECMP is equally common. So most packets would have two NAI. > Very few will more than three flags set. > > Is this an accurate assumption? No one can answer that. > What will be the balance between "implicit" and "explicit" ancillary data? I’m unclear on the distinction you’re making here. Tony