Query entry on TG582 event log

[#1]

So, I got my new TG582 router and set it up Monday, other than the wireless signal being slightly worse than my old trusty(but dying) TG585v7, all seems to be OK. The reason I changed was possible issues with connection drops and to go the route of sorting each simple solution first.
Anyway I was checking the event logs for my router and twice I've had the following entry in the past 24 hours with the little yellow warning triangle:
Jan 14 13:30:39 IDS proto parser : tcp null port (1 of 1) : 113.108.21.16 87.115.191.218 40 41 TCP 12205->0 [S.....] seq 785710706 ack 0 win 8192
The other time was 11.30pm last night. I wasn't actually online with any device at the time of the second event listed and noticed nothing on the first event time while online.
I don't understand a lot of the jargon, so rather than blinding me with a lot of stuff I have no hope of understanding can someone tell me in simple terms what it is, and if it's normal and doesn't need me to do anything else? I've done a few internet searches and see the word 'hacking' a lot, so I'm a bit concerned, but also saw on one site that it was my router blocking the thing and doing it's job. I'd like to know for sure if I need to take no more action?
Thank you.

[#2]

Checked the event log today and the following appeared, with a red circle exclamation mark:
Jan 15 03:01:01 FIREWALL icmp check (1 of 1): Protocol: ICMP Src ip: 114.43.107.5 Dst ip: 87.115.191.218 Type: Destination Unreachable Code: Port Unreacheable
Again I haven't a clue what it means, and still would like to know if something is wrong or whether they are normal events for my router and need no further action?

[#3]

Occasional instances of those type of events are nothing you need be concerned about. I get them and you will find they get mentioned frequently on these forums. They appear to be probes from strange places that your router has blocked; the last one you posted is from Taiwan. The last one carries a red mark because it is an improperly constructed packet.
As I said no need to worry at just a few per day.

[#4]

Thanks so much for your reply.