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VSAT technology and installation >> iDirect Forum: hubs and terminals >> reoccuring downtime

Message started by bcool on Jul 29th, 2008 at 5:47pm

Title: reoccuring downtime
Post by bcool on Jul 29th, 2008 at 5:47pm
hi all, i have an i-direct 3000 modem that goes off at a particular time of the day in the evening for the past four days now but comes up on its own after few hrs. When it's working all the other LEDs are green except the status light that has been permanently off for sometime now.
Pls could this be the problem or wot else could be the problem. thanks all

Title: Re: reoccuring downtime
Post by Eric Johnston on Jul 29th, 2008 at 6:29pm
Three guesses:

1. Severe dish mispointing and small satellite movement.  If the satellite is somewhere down the side of the beam you will lose transmit connection into the hub when the satellite moves even slightly in the wrong direction.  At the same time the measured receive quality will be deteriorated.  Measure the receive quality every hour for a whole day.  Does the quality dip in the evening ?  If not, wrong guess !

2. Effect of temperature on the LNB.  If you have a DRO type LNB this is fine for big outlinks like 27.5 Msps, but if you have a narrow 1 or 2 Msps outlink then the frequency accuracy of the LNB may cause the modem to lose lock on the outlink.  There may be a local oscillator sweep range parameter that can be adjusted, or maybe set the nominal L band receive frequency biased one way a bit.  DRO LNBs have a frequency accuracies of as much as +/- 3 MHz, allowing for both long term drift and extreme temperature limits. Look in the iSite Config Remote Receive. I think there is an LNB LO stability parameter.  If you can measure the tuning stress, do this every hour during the day.  When it goes beyond the limit there will be complete failure and it will start searching.

3. Water/moisture in the feed or cables.  During the day it is hot and water evaporates.  In the cool evening the water condenses.  

Best regards, Eric.

Title: Re: reoccuring downtime
Post by TDMAMike on Jul 29th, 2008 at 9:05pm
Status light being illuminated is indicative of being active in a TRANSEC network.  No worries there.

When you observe service interruption, does the RX light remain green?  

Tough to diagnose from what you have conveyed.  Could be weather attn (afternoon thunderstorms), cron job overwhelming the PPs, RFT issues, etc.  

Would need more info before further fault isolation.

Title: Re: reoccuring downtime
Post by bcool on Jul 30th, 2008 at 11:02am
Thanks for ur contributions, it seems the problem is not even from the i-direct modem since i observed yesterday that, the clients using the wireless connection at another end of the building were browsing. All the lights on the i-direct modem were on, but my Linksys rvs 4000 4port router that the IT manager who was there b4 me configured  as the NAT and DHCP went off. The problem now is that i've only worked with cisco routers and have no idea about how this linksys router works hence i could not even log in to check anything. Pls how do I go about this.

Title: Re: reoccuring downtime
Post by tunde300us on Aug 17th, 2008 at 9:34pm
I guess you just need to talk with the former IT manager to ask for the password and username,am sure you shouldnt habe any probs with that

Title: manager Re: reoccuring downtime
Post by Eric Johnston on Aug 18th, 2008 at 9:14am
Search Google for "Linksys RVS4000 User Guide"  (2.7Mbytes pdf).  It explains how to configure the Linksys RVS4000 router.   Do make every effort to contact the previous IT manager to get the username and password.  Failing that it may be necessary to start from scratch again and reset the router to factory default - but you will lose all previous configuration information. Warning:  Don't do this unless you have fully read the manual and feel confident to start again.  You may have a long downtime.   First, at least try the default username=admin  and password=admin. Gather all information from other working PCs to understand the network and its IP addresses. If the network involves VPN tunnels to other parts of your organisation don't interfere at all and get advice from a more senior IT manager who understands the other ends as well and the encryption keys.

b**t regards, Eric.

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