Which TCP & UDP ports do I need to open up?

You will need to to have the following ports on your security devices or firewalls open for Sinefa to operate.

Ports Required for Sinefa Probe(s)

TCP 443 (HTTPS)
Between: Probe(s) and Sinefa App servers (e.g. ui.sinefa.com)
Connection initiated by: Probe
Use: Communications between Probe and Sinefa App server or Self-host Sinefa server (for sending results/data and probe configuration purposes)
Mandatory: YES

TCP 80 (HTTP) 
Between: Probe(s) and Sinefa software update servers (updates.sinefa.com)
Connection initiated by: Probe
Use: To download new software updates
Mandatory: NO (only required to receive software updates)

TCP 9200 and UDP 9200  (Sinefa NQS testing)
Between: Probe(s) and Probe(s)
Connection initiated by: Either side (this is user configurable)
Use: To generate Network Quality Scores
Mandatory: NO (NQS scoring will not work if these ports are not open)

UDP 123 (NTP) 
Between: Probe(s) and configured NTP Server
Connection initiated by: Probe
Use: To get the correct time for the Probe
Mandatory: YES (otherwise timestamps and results will be wrong)

TCP 53 and UDP 53 (DNS) 
Between: Probe(s) and configured DNS Server
Connection initiated by: Probe
Use: To resolve host and domain names
Mandatory: YES (if using Sinefa App servers) or NO (if using Self-host Sinefa server)

Additional Ports Required for Self-Host Sinefa Server

TCP 443 (HTTPS)
Between: Self-host Sinefa server and Mandrill email servers (mandrillapp.com)
Connection initiated by: Self-host Sinefa server
Use: To invite users into the system and to send email alerts
Mandatory: NO (however user invites or email alerts won't work)

UDP 123 (NTP) 

Between:Self-host Sinefa server and configured NTP Server
Connection initiated by: Self-host Sinefa server
Use: To get and maintain the correct time for the Self-host Sinefa server
Mandatory: YES (otherwise timestamps and results will be wrong)

TCP 53 and UDP 53 (DNS) 
Between: Probe(s) and configured DNS Server
Connection initiated by: Self-host Sinefa server
Use: To resolve host and domain names
Mandatory: NO (however sending of emails and software update won't work)

See Also
How to Setup Network Quality Scoring (NQS)
How are quality metrics measured?