I've encounter a problem where 1 of my PE 8T-V35 ports doesn't support 2Mbps link. But, my others PE with same router model (7206) and IOS version can support the 2Mbps link on 8T-V35 ports. I've already make a back-to-back troubleshooting on the trouble ports with 2Mb bandwidth, its work fine. Hope someone can explain. Thanks.
Is it the modem, CSU/DSU problem ? Did you check w/ the local PTT ? If the back-to-back test is passed, it should be an external issue. Did you try to replace the cable or port ?
Hope this helps.
I don't think its a modem problem. I've already replace the cable and right now, its connected to 4T ports on the same router and its work fine. FYI, at another PE router, 2Mbps line from same provider using same modem/ntu type can be used on 8T port (as i mention earlier).
If this is the case and works w/ another module. The 8 port module may be failure. Try to swap another 8 port module w/ same config. and insert the original 8 port module to another router to identify the cause.
I forgot to mention that i also have try other 8T port at other module on the same PE router. Its still doesnt pick-up the 2Mbps line. Any other troubleshooting ideas?
IC. You carried all isolation steps. What I suspect it is the compatibility issue between the hardware, 8 port module and the PTT devices. This is because it works w/ 4 port but not work w/ 8 port at your site. If you have chance to test the 'non-working' 8 port module at the working site where installed 8 port then it will prove the 8 port is working.
Any chance to ask the PTT to change another brand of modem just to isolate this issue and not means the modem is failure.
What do you think ?
And, is the IOS that you are using the same as the another working 8 port router ? If yes, it isolated the software issue, if not, it is no harm to sync. the IOS release.
Good luck and hope this helps.
Jacky, the router model and IOS is the same. And both 2Mbps link from PTT have the same brand modem.
I haven't try to test the non-working 8T at the working router because this will involve downtime to the PEs.
The main issue is to isolate the problem, so did the PTT swap the modem ? You swapped the card but still not work. I still think it is the problem from the PTT.
However, is there any chance the problem of the slot ? Tried to insert the module to another slot or test it w/ another chassis and same modem ?
I haven't ask PTT to change their modem yet. Regarding the slot problem, I only test another 8T module at another slot on the same router, but the 2M line still doesn't pick-up.
I just wonder, if its the modem problem, why its can be used at 4T port?
As I mentioned before there may some issues from the PTT side. You tested the 8T at different chassis and works, you also tested the 4T and works. It looks like compatibility issue. What I suggest you need to list out all possibility and test it one-by-one.
However, any error log from the router when you use the 8T connect to the PTT ?
No error log, only the interface show protocol down. But the protocol will be up a few seconds, and then it will down again. Even if the protocol are up, I can't ping to the next hop (CE). Just to correct you, its doesn't work when i tested 8T at different chassis.
Thanks for the update. So it means the 8T module is failure / broken that cause the problem. Did you try to replace another 8T module and test again ?