Internet
From Netfilter Workshop 2017
At your request, we will deliver MEO Enjoy (by Portugal Telecom) sim cards with 30GB traffic for 14 days.
Please, confirm you need a sim card in the attendance wiki page.
If you're arriving to Portugal before the workshop and you cannot wait for whatever reason, you may want to buy it yourself at some "Loja MEO" ("Loja" means "shop" in Portuguese) that you can usually find in main Portuguese cities.