Can someone please tell me what protocols and port numbers I need to add to my Prec 5 DSCP QoS configurations to ensure that any video traffic gets pushed out first if there is congestion.

Is it just RTP and H.323 protocols?

Thanks :)

  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could post and accept your own answer.
    – Ron Maupin
    Dec 20, 2020 at 18:31

2 Answers 2


As you mention RTP and H.323 you are probably prioritizing videoconferencing traffic. I won't go into the details of H.323 advantages over SIP, so I''ll just go over H.323 protocols.

Also Prec 5 is really just EF (Express Forwarding). However, EF queues are very small which could lead to dropped packets. I would suggest using AF41, as you're not going to get a better advantage giving the audio portion of the videoconference a higher priority than video. Use AF41 for both audio and video.

Here are the recommended ports for the H.323 protocol.

80 Static TCP HTTP Web Interface

389 Static TCP LDAP

443 Static TCP HTTPS & Port Tunnelling

1718 Static UDP Gatekeeper Discovery

1719 Static UDP Gatekeeper RAS

1720 Static TCP H.323 Call Setup

2253 - 2263 TCP Sony endpoints

2326 - 2485 UDP Cisco/Tandberg endpoints

3230 - 3235 TCP Polycom endpoints

3230 - 3280 UDP Polycom endpoints

5001 TCP & UDP Polycom PPCIP client

5004 - 6004 TCP & UDP ClearOne endpoints

5060 TCP & UDP SIP endpoints


5555 - 5574 TCP Cisco/Tandberg endpoints

6000-6006 TCP & UDP Librestream endpoints

8080 Static TCP HTTP Server Push (optional)

9400 - 9406 TCP & UDP AudiSoft endpoints

9800 - 9806 TCP AudiSoft Server/Gateway

9810 - 9822 UDP AudiSoft Server/Gateway

15100 Static TCP NetPoint Q.931 Call

15101 Static TCP NetPoint Default

15102 Static UDP NetPoint Default

22136 Static TCP MXM endpoint administration

  • 2
    Lumping common ports like 80, 443, and 8080 into a low-drop threshold queue like this renders the queueing strategy useless. I know this website (where this list is from) says you need to have these ports open with NAT, but that doesn't mean you queue it that way.
    – Ryan Foley
    Oct 5, 2014 at 19:46
  • Good strategy demands you ACL-off your upper queues to block people from self-attaching and cheating the system. With the lack of clarity in the question, mentioning "all" the ports is a good idea. I am am pretty sure Network Ninja knows how to queue correctly.
    – Jaxxs
    Oct 5, 2014 at 20:10
  • The OP is "tell me what protocols and port numbers I need". That seems straightforward to me.
    – Ryan Foley
    Oct 5, 2014 at 20:51
  • So giving a little extra is somehow a bad thing? Why not post your own answer? :-)
    – Jaxxs
    Oct 5, 2014 at 21:41
  • Hi Jaxxs, thank you for your answer. I already have LDAP, HTTP and HTTPS in other queues. I also have RTP in Prec 5. I would like to prioritise video traffic in PREC 4 on my cisco router. (my mistake in my original question). Usually the command would be "match protocol rtp video" under class-maps. I'm looking to find out what protocols and port numbers are included in the "rtp video" command in cisco IOS. Thank you Oct 5, 2014 at 21:51

Depending on the level of control you have over your network environment (or how much you trust the devices connected to it), you could also look into having the video devices themselves tag their traffic with the appropriate DSCP value, and then mapping any traffic with that value to the queue you want. I have found this to be easier than listing the protocols, since the video terminal has the best knowledge of its protocols, ports and so on. They often have a fairly consistent approach of this, tagging the media streams as AF41 (or 43 ? haven't looked this up recently). Again, this assumes you can trust the incoming tags from the LAN on your router.

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