Which Ports are used by SwyxWare (<= v6.01) (kb2308)

The information in this article applies to:

• SwyxPhone L440
• SwyxPhone L400
• SwyxPhone L420
• SwyxFax til v6.01, SwyxWare til v6.01

[ Question | Answer | Further Informationen ]

Question

Which Ports are used by SwyxWare and how do I have to configure my Firewall?

Answer

Information about the used ports of other SwyxWare version can be found here:

• Which Ports are used by SwyxWare (Overview) (kb4498)

SwyxWare does consist of:

• Clients:
  • SwyxIt!
  • SwyxPhone L400
  • SwyxPhone L420, L420e, L420s
  • SwyxPhone L440
  • SwyxPhone L100
• Server:
  • SwyxServer
  • SwyxGate
  • LinkManager
  • ConferenceManager
  • PhoneManager
  • ITSPManager
  • SwyxFax Server

Connections can be devided into 2 phases: callcontrol (connection establishment/destruction) and the data phase (transmission of audio- of faxpackets).

The audio data will always be transmitted via UDP. Faxdata may be transmitted via UDP or TCP, by default UDP is used up to the current version of SwyxWare (4.10). For all these data transmissions the following source- and destinationports are used:

Callcontrol is done with the help of the following protocols:

• H.323 -> TCP + UDP
• SIP -> TCP + UDP
• Microsoft DCOM -> not deterministic
• CorNet -> TCP
• ITSP -> TCP

H.323 is a kind of umbrella standard and consists of the protocols RAS (UDP), H.225 and H.245 (both TCP).
Registration of clients is done via RAS and H.225/H.245 is used for callcontrol (e.g. establishment of calls and opening of audio channels etc.).
Some of these protocols use well known ports for the initial connections. The following table shows which ports are used:

¹ Technically it's impossible for different applications to listen at the same port. In case of installation of SwyxServer and LinkManager respectively Gateway on the same machine port 65000 and 65001 is used by the LinkManager and port 2000 is used by the Gateway.
² For the same reason as mentioned above, the LinkManager listens on port 65002 for SIP message, because the SwyxServer claimed port 5060 for SIP.
³ More details are available here:

http://msdn.microsoft.com/library/en-us/dndcom/html/msdn_dcomfirewall.asp
http://support.microsoft.com/support/kb/articles/Q248/8/09.ASP
http://support.microsoft.com/support/kb/articles/Q300/0/83.ASP

The next table shows the used call control protocols and the necessary ports for each product:

Basically audio and fax data will always be transmitted directly between caller and callee, if both are located in the same site. This is different from the call control messages, which are always exchanged via the SwyxServer. Some clients don't communicate directly with the SwyxServer (as SwyxIt! does), but use in case of L420 phones the Phonemanager and in case of L100 phones the ITSPmanager for call control.
In configurations with more than 1 site there will always be at least one LinkManager. This LinkManager transfers all call control messages between the two SwyxServers (one server for each site) via H.323. Additionally this LinkManager transfers the audio and fax data between two parties calling from one site to the other. If necessary, the LinkManager will transcode the audio data.
This means, if SwyxIt! A from site Aachen establishes a call with SwyxIt! B from site Bochum the following will be done:

1. SwyxIt! A will contact via DCOM the local SwyxServer of site Aachen.
2. The SwyxServer of site Aachen will contact the SwyxServer of site Bochum via the LinkManager using H.323.
3. The SwyxServer of site Bochum will contact the SwyxIt! B via DCOM as the called party.
4. In case SwyxIt! B does pick up the call the LinkManager will transfer the audio data between SwyxIt! A and SwyxIt! B. The SwyxServers are not used at all for transmitting the audio data.

Please take a look at the following, additional articles:

• Selection of local IP addresses by the LinkMgr for remote and local side of a link. (kb2247)
• Connecting a SwyxIt! to a SwyxServer through a firewall (kb2623)
• How to configure a VPN connection for a SwyxIt! user (kb2240)

Further Informationen