Information for Internet CALL This page is originated from http://dsp.ee.cuhk.edu.hk/proj/icallinf.html. You can find the most updated one there. System Requirement of Internet CALL PC Version * 486DX2-66 CPU * 8MB DRAM * Microsoft Windows 95 or Microsoft Windows NT * 9.6kbps modem under SLIP/CSLIP/PPP or fixed Internet connection using 32-bit Winsock library * Windows compatible full-duplex sound board or two half-duplex sound boards for full duplex or one half-duplex sound board for half-duplex --------------------------------------------------------------------------- System Requirement of Internet CALL SUN Version * SUN SPARCStation series workstation (I've tested 4, 5, 10, 20 and Ultra 1) * Audio hardware support * Solaris 2.3, 2.4 or 2.5 * Motif 1.2 run-time library --------------------------------------------------------------------------- Tips for Internet CALL How to uncompress * For PC version, type "pkunzip chatxxxx.zip" * For SUN version, type "gzip -d < chatxxxx.tar.gz | tar xvf -" How to run * For PC version, type "chat" at DOS prompt to run. * For SUN version, type "./chat" at Xterm to run. How to use Internet CALL * New Connect - Start to call remote side. The hostname field is Internet hostname or the IP address of the remote side. The port number is the binded port number of remote daemon. You may also use the "Locate" function to search the one you call to. * Domain Specific Locator (DSL) - A function that is used to find the remote receiver who has a dynamic IP address. The hostname field is any hostname within the domain of your receiver. The user name field is the alias of your receiver. The timeout field is the number of seconds to wait for the response. * Preferences * Silence threshold (default 500) - the threshold value to be regard the audio signal as noise or voice. The larger the value, the more is the resistance to background noise. * Play delay - the number of frames to be collected before putting them to the sound card. More overhead time is needed for smaller delay but you will gain in the response time. This parameter can be optimized in calibration on Win32 version. * Record delay - the number of frames will be bufferred by the sound card at one time. Lower delay can decrease the response time but increases the overhead time which causes lower speech quality. This parameter can be optimized in calibration on Win32 version. * Internet connection speed (PC Win32 version only) - the speed of your internet conection. This parameter determines the amount of headers to be inserted to the voice data to comply with the data rate. * User name - the alias that others can find you using the Domain Specific Locator. * Daemon port (default 6170) - the TCP port binded for waiting for connections. You can change it to other unused ports if the default one is in use and the Domain Specific Locator can still find you. * Half-duplex mode only - it indicates both local and remote the type of connection to be made. If you are having a full-duplex sound card, you can clear this check box. This parameter can be optimized in calibration on Win32 version. * Coder - (PC Win32 version only) there are two coders at this time for selection: One needs less computation but have lower voice quality. One needs more computation to produce better quality. Pentium 90 or faster users are recomended to use the later one. This parameter can be optimized in calibration on Win32 version. * Intial quality - the initial value to be set for defining the computation complexity when a call is started. This parameter can be optimized in calibration on Win32 version. * Calibration (PC Win32 version only) - An automatic calibration function to test and optimize the system parameters. * The Phone Button - a one-click button for making connections, answering calls, toggling in half-duplex mode and hanging up. The responses are shown below. * Hangup ->clicked-> New Connect * Ringing ->clicked-> Chat or Send * Chat ->clicked-> Hangup * Send ->LEFT clicked-> Receive * Send ->RIGHT clicked-> Hangup * Receive ->RIGHT clicked-> Hangup Miscellaneous * To adjust the playing and recording volume, for PC, you can use the "Volume Control" program in Windows, and for SUN, you can use the "audiocontrol" command. * The Domain Specific Locator is now binding a UDP port at 6171. If your computer cannot bind this port or this port is used already. Please report to me. Troubleshooting * When I started Internet CALL, it shows me a lot of error messages, "Unable to create socket", "Unable to bind port", "Unable to listen to port", ... Ans:It is due to the WSOCK32.DLL is not activated. Internet CALL for Win95 requires 32-bit Winsock library with connected in SLIP/PPP or fixed Internet network connection. * I have entered the hostname of remote in the "Connect" dialog but it displays "Unable to resolve hostname". Ans: Please ensure you have typed the hostname correctly. If the same error message is appeared again, your DNS may not have the hostname you typed in its database. You can ask your remote to give you the IP address instead. Internet CALL supports IP address field also. * I used the domain specific locator to find my friend in a domain, but it always replies "Unable to find user in the domain specified". Ans: If you are using Icall version 0.4b4 or ealier, please download the version 0.4b5 or later since version 0.4b4 used a methodology that is not working on all domains. Some domains may refuse requests. If you are using version 0.4b5 or later, please ensure the hostname you entered is really on the domain of your caller. You can confirm it by asking the remote whether the hostname you typed has the network address its domain, i.e. the first 3 numbers in the IP address "abc.def.ghi.xxx" are the same. Also, please confirm the user name typed is the name that your caller has set in the "Preferences" setting. If it is still not working, please contact me. * I have connected with a friend but I cannot hear anything. Ans: Please ensure the cables of your audio system is plugged properly and the volume setting is not too low. If it still does not work, please see in the status bar the third column if you can see the number is accumulating. If the number is freezed, your remote may not be talking or its data are all lost in an unstable transmission pathway. * I cannot record anything or when I start talking, the indicators do not display what they should be. Ans: Hang up the call and try to increase your record delay to reduce the overhead time and then connect again. If it is still not working, please contact me. * The troubleshooting section is not completed yet. If you have any problem that is not listed, please feel free to send emails to cmwu@cixt.cuhk.edu.hk. Your kindly response will surely enhance our product. Frequently Asked Questions (FAQ) * What is Internet CALL? Internet CALL is a software providing point-to-point real-time voice communciations over Internet. It can be operating in half duplex or full duplex mode. Internet CALL is a free product developed by Department of Eletronic Engineering, the Chinese University of Hong Kong, under the project "Interactive Voice Communications systems". Free downloads can be obtained from http://dsp.ee.cuhk.edu.hk/proj/icalldl.html. * How Internet CALL makes a connection? Icall is aiming at providing private coversations over two points. It does not plugged into any IRC or Web servers for registration. i.e. You would not be called by anyone that you do not know since they cannot find you. However, for the people you want to receive their calls, you have to tell them the hostname you are using. When they call you, they just need to input the hostname you told to them and Icall will connect them with you directly. * What is domain-specific locator (DSL) and how it works? Domain-Specific Locator (DSL) is a tool for solving the dynamic IP allocation problem. It can be used to find a remote user at a specific domain but may have different IP addresses. DSL asks you to fill in one of the hostnames in the particular domain as well as the name of user you want to find. DSL will try to contact with all hosts that has the same netmask "255.255.255.0" of the IP address of the hostname you typed. i.e. the 254 hosts of IP addresses abc.def.ghi.xxx will be searched. If Internet CALL is activated, DSL will check if the name you typed matches the one in the "Preferences" setting. of the remote side If they are matched, DSL will tell you it has found the user you want. * What does the daemon port means? The daemon port is a number that the Icall daemon binds. It should be 6170 by default but it fails to bind at this port, you can change to another one. However, you have to tell your friends for your particular daemon port number, or DSL can it out for them. --------------------------------------------------------------------------- Last modified August 12, 1996. Copyright © 1996 EE CUHK. All rights reserved.