We try to use the serial port of a max transit to remotely connect to the console port of a switch (alcatel omniswitch) and encountered a strange issue…
There is absolutely no activity on any of the serial lines when the 2 devices are connected (all 0V instead of defined RS232 levels).
I looked further into this issue and both alcatel and transit are using the MAX3243 line driver which has a an autoshutdown function when no valid RS232 level is received on RXD. The problem is, both pepwave and alcatel stay in the shutdown mode since neither is seeing a TXD signal from the other. My pc’s serial port behaves the same, with the only difference that when I open terraterm, it pulls TXD high (+6V) and RTS/DTS low (-6V). In my opinion this is a bug, since you either shouldn’t use the autopowerdown function on a DTE or you should at least disable it when a serial connection is established trough the web link of via remote terminal over IP.
At the moment the serial port feature is quite useless and it’s not limited to the alcatel switches. Is there a way to fix it through a firmware upgrade?
At the moment only one location, since the proof of concept is kind of stuck because of this issue. The serial port wasn’t a real perk for our department, but our collegues from the WAN department are really interested.
They have about
15-20 remote sites and there is always a risk that a remote network becomes inaccessible during an update/configuration change. Having console access to the root stack is a real advantage and allows to lower the risk
assessment for change requests.
In our department (mobile WAN access for news gathering and live broadcasts) we mainly use HD4’s (14) and transit(5)/transit duo’s(7), but are still expanding the network.
For us as customer there are 2 issues we find annoying.
the LTEA version of our HD4’s have a lot of modem issues (prior to buying the equipment we leased 6 HD4’s for a year and they didn’t have the problem, but it was the regular LTE version, not the one with the advanced
modems)
the serial port issue.
Mainly because in the first issue there has been a lot of mailing between us, Frontier and peplink, but until now no real progress was made. The serial port is less important, howerver a dealbreaker for a larger purchase
from our collegues in the future, but in my
opinium it should be easy to fix in a firmware update.
@Derek, thanks for sharing the valuable information with us, that definitely helps us to understand more about your deployment scenario. I am sure our teams will find the information to be useful too.
Do you mind to share the Peplink support ticket number(s), if you have any on-going case(s) on the MAX HD4-LTEA, so we can review the case(s) status?
