Latency for responses to DHCP Solicit and Router Solicit

[bimmerdriver]

While testing the fix for "do not wait for RA", I've noticed that the response to DHCP solicit messages is almost instantaneous (8-9 ms), but the response to router solicit is longer, typically 1 second, but occasionally 2-4 seconds. I have a contact in the engineering department of my ISP so I sent him an email asking if there was any explanation for this. He agreed that since the RA usually comes almost exactly 1 second after the RS, it must be a default, but he is going to look into it to confirm why, since the response to the DHCP solicit is so much faster. The edge router appears to be Alcatel, based on the MAC address in the capture.

I'm interested to know if this latency is typical or not. If you know what the latency is on your network, please reply.