There's actually more than one way to get Changi to work with a news provider. Chanx is one way, it represents a pull feed. Chanx asks the news provider what's new in a group and then iteratively requests the articles pulled down. Some providers, Netcom for example, and many others, I hear, don't support pull feeds because they are too resource-intensive (It turns out that Usenet news is the biggest drain on their systems and a pull feed can lead to very abusive behavior). Netcom uses an INN (Internet Network News) news server. They've configured it so that the crucial commands for a pull feed (eg. "NEWNEWS" and "ARTICLE <message-id>") aren't available to their news-feed customers.
What they do support is a push feed. On a push feed the news server periodically connects to your local Changi server and dumps news into its supported groups (those that you and the provider have agreed to). This way the provider gets to carefully control the conditions and timing of news movement. To perform a push feed the remote server iteratively sends an NNTP command called "IHAVE" to Changi with the articles' Message-ID as the argument. If Changi hasn't gotten this article, the remote sends it (all part of the IHAVE exchange).
If you're not sure what your provider offers for an interface TELNET into the provider's news server (remember to use NNTP port 119). Issue the HELP command and it will tell you what commands it supports. If you see NEWNEWS and ARTICLE, you can use Chanx without any special option to pull the news. If you see XOVER and ARTICLE, you can use Chanx with option -mx. Even if ARTICLE is supported, but neither NEWNEWS nor XOVER, you can call Chanx with option -mw.
However, if you don't see ARTICLE, but do see IHAVE then you will have to configure for a push feed. You'll need to independently talk to your provider about how their push feed is supported. Some providers have an automated way of allowing you to configure the push feed by sending email in a precise format to their news support robot. Assuming you have a news-feed as part of your agreement with the provider, they will have to tell you whether their server is configured manually or automatically.
Finally, there is one last problem. Everything we've talked about here deals with receiving the news -- not posting news back to the provider's news-server. If you find that your provider only offers a push feed, they will most likely require that posts also use IHAVE to push articles back from Changi-to-provider. Changi can do this if you set up a proper newsfeeds file as shown in the following example.
ME:*,!control,!control.*,!junk/!local:: news.ping.de:/!local:L,Tp:rnews -Hnews.ping.deChangi will call Rnews on each local post it receives and write the article immediately to the standard input of Rnews. In turn, Rnews will transmit the article to news.ping.de using the IHAVE protocol.
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URL: changi/manual/pushfeed.html Created: 27 October 1996 Revised: 21 December 1996 Author: harald@os2point.ping.de |