Difference between revisions of "RouterBoard N card power issues"
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'''PLEASE BE AS SPECIFIC AS POSSIBLE''' - mention at least the following: | '''PLEASE BE AS SPECIFIC AS POSSIBLE''' - mention at least the following: | ||
| − | + | * rb type | |
| − | + | * RouterOS version | |
| − | + | * the number of cards | |
| − | + | * the type of cards (R52/R52n/R52hn/XR71 etc) | |
| − | + | * the power supply (POE/Direct DC) | |
| − | + | * If using POE | |
| − | + | * cable type ([http://en.wikipedia.org/wiki/Cat5e Cat5e] normal/shielded/Cat6 etc) | |
| − | + | * distance between injector and rb | |
| − | + | * measured voltage | |
| − | + | * at supply | |
| − | + | * at RB | |
| − | + | * how many RBs on the same power supply | |
= The Problem = | = The Problem = | ||
| − | A typical Mikrotik [http://www.scoopdistribution.co.za/product_info.php?cPath=100_34&products_id=745 | RB433] will quite happily power 3 [http://www.scoopdistribution.co.za/product_info.php?cPath=100_102&products_id=512 | R52] or equivalent cards on a standard 18v 0.5A POE injector over more 30m or more of Ethernet | + | A typical Mikrotik [http://www.scoopdistribution.co.za/product_info.php?cPath=100_34&products_id=745 | RB433] will quite happily power 3 [http://www.scoopdistribution.co.za/product_info.php?cPath=100_102&products_id=512 | R52] or equivalent cards on a standard 18v 0.5A POE injector over more 30m or more of Ethernet [http://en.wikipedia.org/wiki/Cat5e Cat5e] cable. Unfortunately once an 'n' card is added, this is no longer the case. |
| + | |||
| + | The standard issue that arises once 'n' cards are added is that the router board reboots at regular intervals. The problem can be triggered by running scans on all of the wireless interfaces at the same time and waiting up to 10 minutes. | ||
| + | |||
| + | Other symptoms include: | ||
| + | * router config reset after reboot | ||
| + | * instability in previously stable links, especially during periods of high load | ||
| + | * high pitched whining noise coming from the rb | ||
| + | * POE network port jabbering and loss of ethernet connectivity, with the wireless links remaining active | ||
| + | |||
| + | = Causes = | ||
| + | The cause of these problems is a lack of power to the routerboard's CPU and wireless slots, which is in turn caused by either a lack of power to the power converter, or the power converter being overloaded and mis-behaving. | ||
| + | |||
| + | == Lack of input power == | ||
| + | This seems like an obvious one - if the routerboard isn't provided with a clean, on-spec power supply, it will mis-behave. Unfortunately the use of POE can hide this. [http://en.wikipedia.org/wiki/Cat5e Cat5e] cable is 0.x mm thick and as such will lose x volts/m @ x A. In other words, a 24v 1A POE injector will only provide the routerboard with x W of power after running along 30m of [http://en.wikipedia.org/wiki/Cat5e Cat5e] cable. Increase that to 60m and you've got a serious, but hidden problem. | ||
| + | |||
| + | Start by reducing the network cable length as much as is feasible, then try a higher rated POE injector. Finally, you should go for direct DC power to the rb. | ||
| + | |||
| + | '''HINT''' Sometimes POE efficiency can be reduced by poorly crimped connectors or damaged network cable - check or re-crimp if possible. | ||
| + | |||
| + | == Overloaded | ||
| + | This is what gives the 'n' cards a really bad name - the onboard power converters for the routerboards are limited by design and in most cases cannot supply enough power to both the wireless cards and the CPU. Once this limit has been reached, the power converter '''should''' shut down the board, but it would appear this is not always the case - so presenting the user with the above-mentioned set of issues. | ||
| + | |||
| + | |||
| + | |||
| + | [http://www.scoopdistribution.co.za/product_info.php?cPath=100_34&products_id=745 | RB433], [http://www.scoopdistribution.co.za/product_info.php?cPath=100_34&products_id=746 | RB433AH] and [http://www.scoopdistribution.co.za/product_info.php?cPath=100_34&products_id=813 | RB493AH] routerboards. | ||
| + | |||
| + | = Solutions = | ||
| + | The most obvious solution is to use | ||
[http://www.scoopdistribution.co.za/product_info.php?cPath=100_34&products_id=746 | RB433AH] | [http://www.scoopdistribution.co.za/product_info.php?cPath=100_34&products_id=746 | RB433AH] | ||
Revision as of 23:29, 6 December 2010
Introduction
This page is a work in progress, describing the steps people have taken to resolve power issues related to the 'new' Mikrotik R52hn and R52n cards. Please add your experiences and solutions to the problems here.
PLEASE BE AS SPECIFIC AS POSSIBLE - mention at least the following:
- rb type
- RouterOS version
- the number of cards
- the type of cards (R52/R52n/R52hn/XR71 etc)
- the power supply (POE/Direct DC)
- If using POE
* cable type (Cat5e normal/shielded/Cat6 etc) * distance between injector and rb
- measured voltage
* at supply * at RB
- how many RBs on the same power supply
The Problem
A typical Mikrotik | RB433 will quite happily power 3 | R52 or equivalent cards on a standard 18v 0.5A POE injector over more 30m or more of Ethernet Cat5e cable. Unfortunately once an 'n' card is added, this is no longer the case.
The standard issue that arises once 'n' cards are added is that the router board reboots at regular intervals. The problem can be triggered by running scans on all of the wireless interfaces at the same time and waiting up to 10 minutes.
Other symptoms include:
- router config reset after reboot
- instability in previously stable links, especially during periods of high load
- high pitched whining noise coming from the rb
- POE network port jabbering and loss of ethernet connectivity, with the wireless links remaining active
Causes
The cause of these problems is a lack of power to the routerboard's CPU and wireless slots, which is in turn caused by either a lack of power to the power converter, or the power converter being overloaded and mis-behaving.
Lack of input power
This seems like an obvious one - if the routerboard isn't provided with a clean, on-spec power supply, it will mis-behave. Unfortunately the use of POE can hide this. Cat5e cable is 0.x mm thick and as such will lose x volts/m @ x A. In other words, a 24v 1A POE injector will only provide the routerboard with x W of power after running along 30m of Cat5e cable. Increase that to 60m and you've got a serious, but hidden problem.
Start by reducing the network cable length as much as is feasible, then try a higher rated POE injector. Finally, you should go for direct DC power to the rb.
HINT Sometimes POE efficiency can be reduced by poorly crimped connectors or damaged network cable - check or re-crimp if possible.
== Overloaded This is what gives the 'n' cards a really bad name - the onboard power converters for the routerboards are limited by design and in most cases cannot supply enough power to both the wireless cards and the CPU. Once this limit has been reached, the power converter should shut down the board, but it would appear this is not always the case - so presenting the user with the above-mentioned set of issues.
| RB433, | RB433AH and | RB493AH routerboards.
Solutions
The most obvious solution is to use
