The online PNR status as well as seat availability queries can be fetched from computerized reservation applications, which happen to be available to public from 08:00 hrs. IST to 20:00 hrs IST on weekdays and through 0800 hrs IST to 1400 hrs IST every Sunday. These kinds of web-based reservation applications are shut down daily about 2300 hrs IST as well as booted around 0500 IST hrs on weekdays. Every Sunday the shutdown is done earlier.
Because of the dynamic changes taking place within the PNR status updating and the availability positions, both of these types of queries need to be fetched from online booking programs, hence the non- availability of them immediately after some timings.
As mentioned above, for the PNR status and seat availability queries, the result is fetched from computerized booking applications at the five websites, viz. New Delhi, Mumbai, Kolkata, Chennai and Secunderabad.
If there is any network link failure, or the network lines have become congested, then this mistake message is displayed. It would so happen that you are receiving seat availability and PNR status information in say trains coming from New Delhi and Kolkata, but not for trains originating from Mumbai
