Tag Archive
Clone Wars
In this post I wish to discuss a common coding error that can result in a module running out of or at least seriously depleting the available number of stcp device clones for use in creating TCP sockets.
Host versus Hosts
There has been a fair amount of confusion over the difference between the host file and hosts (plural) file. Both files should be in the >system>stcp directory but there the similarity ends. The hosts file is used for IP address to name resolution. Depending on your configuration you may or may not need a hosts [...]
The Importance of -1
Don’t worry, despite the title I haven’t reverted to math nerd mode. The topic is not number theory but socket programming and a coding mistake that I have seen way too often. The code fragment in figure 1 demonstrates the mistake. There is a main while loop that loops forever calling select and waiting for [...]
STCP’s Duplicate IP Address Detection
STCP has had duplicate IP address detection for quite some time but a change to how Microsoft Windows 2008 and 7 behave has added an interesting wrinkle. First let’s review how it works. Duplicate IP address detection relies on the address resolution protocol (ARP). The packet_monitor tool shows an ARP packet in two lines as [...]
packet_monitor and the TCP options supported in OpenVOS 17.1
Starting with OpenVOS 17.1, STCP supports the time stamp, selective acknowledgment, and window scaling TCP options. This will allow for a more efficient data flow when TCP segments are dropped or when sending data over a high bandwidth delay connection (a connection over a link where the minimum bandwidth * overall latency > 65536). The [...]
