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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 :)

NetworkNinja
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  • 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 '20 at 18:31

2 Answers2

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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

5061 TCP SIP TLS

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

Jaxxs
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    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](http://www.c21video.com/firewall.html) (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 05 '14 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 05 '14 at 20:10
  • The OP is _"tell me what protocols and port numbers I need"_. That seems straightforward to me. – Ryan Foley Oct 05 '14 at 20:51
  • So giving a little extra is somehow a bad thing? Why not post your own answer? :-) – Jaxxs Oct 05 '14 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 – NetworkNinja Oct 05 '14 at 21:51
  • Hey Network Ninja, thanks for the info. An unfortunate ban on comments from newbies to this site (like me) has made answering questions a little difficult. I can't comment for clarity or for anything else for that matter. – Jaxxs Oct 05 '14 at 22:01
  • Well, "match protocol rtp video" or "payload-type" works if you have an NBAR enabled router. Just use payload-type which matches payload type values 24-33. Or you can use: "class-map Gi0" "match ip rtp (starting port-2000 to 65535) (range-0 to 16383)" or you can simply match on an ACL in your class map - "ip access-list rtp_video permit udp any any range 2001 1500" – Jaxxs Oct 06 '14 at 00:48
  • Thank you Jaxxs, however I'm still a little confused here. Lets say I do have an NBAR enabled cisco router. I am using "match protocol rtp video" command. However instead of using NBAR and using the predefined protocol values defined in the payload types, I would like to use an access list which states exactly what type of protocols and port numbers needed to match the "match protocol rtp video" command – NetworkNinja Oct 06 '14 at 12:05
  • I hope that made sense, to summarise: What protocols and port numbers do I need to add to my ACL's to produce the exact same result as If i were to use "match protocol rtp video" - thank you in advanced – NetworkNinja Oct 06 '14 at 12:06
  • I think I know what you are trying to do, but I don't think you can do it. RTP data is to be carried on an even UDP port number and the corresponding RTCP packets are to be carried on the next higher (odd) port number, within the ranges I mentioned above. This means apps using RTP can use any randomly chosen UDP port. – Jaxxs Oct 07 '14 at 00:27
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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.

Jeremy Gibbons
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