Network

Optimization

To optimize the network:

  1. Choose a network card in the drop down menu.
  2. Set speed and if applicable duplex for the network card.
  3. Choose a connection type in the drop down menu.
  4. If applicable set MTU, kernel socket buffer, TCP, UDP and Local stream sockets values.
  5. Push the "Apply" button
  6. Done!

Choose network card: (1-2)

First step in optimization is to choose a network card. Primary (en0) is usually an Ethernet card, the secondary (en1) is usually an Airport card. Cocktail provides an indicator which displays the current card's adapter status.

When a active network adapter is chosen one can set speed (Auto select, 10BaseT/UTP, 100BaseTX and 1000BaseT) and duplex to Half, Full, Full with hardware-loopback or Full with flow-controll. Airport cards don't support speed or duplex settings, these settings are only applicable for Ethernet other cards which have speed and duplex settings.

Cocktail does provide the possibility to force speed and duplex settings. Forced non-valid speed and duplex settings can result in problems in communication with the router. When "force speed and duplex settings setting" is disabled, Cocktail will try and use chosen configuration. If that doesn't work Cocktail will automatically change speed and duplex to a valid setting.

Choose connection type: (3-4)

When proper network card have been chosen the next step is to set the connection type. One can chose between a set of predefined or create a custom connection type. Besides the default and custom option the following predefined connection types can be chosen in the list:

Cocktail also permits you to define MTU size and kernel socket buffer size (kern.ipc.maxsockbuf).

TCP
Receive window size: net.inet.tcp.recvspace
Send window size: net.inet.tcp.sendspace
Slow link window size: net.inet.tcp.slowlink_wsize
Delayed ACK: net.inet.tcp.delayed_ack
NewReno Fast Recovery: net.inet.tcp.newreno
RFC-1323 extensions: net.inet.tcp.rfc1323

UDP
Outgoing datagram size: net.inet.udp.maxdgram
Receive buffer size: net.inet.udp.recvspace

Local stream sockets
Receive buffer size: net.local.stream.recvspace
Send buffer size: net.local.stream.sendspace

Apply settings: (5-6)

When pushing the "Apply" button Cocktail will apply all settings and create a "startup item" in /Library/StartupItems which enables Mac OS X to use the same settings after a reboot. By creating a startup item Cocktail solves the problem with configuring Mac OS in the Terminal or by using Network preferences where these changes are set to default on reboot.

If problems occurs after changes to network setting with Cocktail (i.e. selected Dial-up preset when a DSL connection is present) you can remove the folder /Library/StartupItems/Cocktail and reboot the computer. If Mac OS X prevents you from delete the folder Mac OS X can be booted in SafeMode by pressing and hold Shift while booting. If problems occur after changing the network settings, you can remove the folder /Library/StartupItems/Cocktail and reboot the computer to switch back to the previous settings. If Mac OS X prevents you from deleting the folder, you can boot Mac OS X into SafeMode by holding the Shift key while booting and then remove the folder.

Online information