Switch is rightly called as heart of network and to make sure the heart is properly beating and is able to pump in the right blood in right vein and artery should be handled with topmost priority. Now to understand few of the slips which can result in unforeseen downtime we are here with this post to save you from such flip ups. You can always give me a ping in case you face any trouble with the switch. But while you send in the concern to me please make sure to share the make, hardware and software versions of the switch in question with the steps taken in resolving the issue. I don’t claim myself to be 100% able to solve the issue but can route you to the right direction of solution in fixing this.
Coming back to the topic in hand the common slip ups which doing Switch Operation and Management. Below are the common issues with the switch and the resolution to the same. The commands are different for different vendor switches but the basic idea remains the same.
1. Cross Connection:- First we know that there are cross connection complaints in a route with 1 TG. Following are the checks which needs to be done before troubleshooting this issue as the resolution may be in this questions itself. I am answering the question making it tougher so you can probably look at the lighter ones by yourself:-
Question:- Is the TG bothway or oneway?
Look for the CIC Selection method there must be some issue with in it. Ideally it should Even to odd. If the cic selection is ok check for congestion if route is congested divert some traffic from the route as once the route is congested the node will look for any available cic. This is not a ideal way things should be.
if still this issue persist it is an issue of either the E1s or cic mismatch.
2. Voice Quality poor:-
It is an issue primarily with physical E1 and could be an issue of echo cancellation parameter not defined or improer definition for the route.
3. Calls not maturing or call Initiation failed at a particular route:-
It is due to the blocking of route or the TG or the signalling is either down or defined on a fluctuating E1.
The Issues could be many but the work around is possible if we are clear with the basic concepts and some times inter vendor connectivity have common known issues which can fixed by the vendor ticket management team. Another issue with this route could be signalling congestion. It is always recommended to have LSL links first if they are already 16 Links and beyond that HSL Links will solve the purpose.
Always avoid below Slipups in Switching Operations and Maintenance:-
A. Always be alert while defining Definition of Point code and Signalling link code and Signalling Link
B. While defining the CIC Selection method and CICs for a route.
C. Testing on live traffic should be done by opening one or two timeslots/E1 and doing a direction call. If it is not possible routing a particular number to a test route and testing the calls one by one.
D. Routing changes should be done by a single person a particular set of people only. And specially for systems like Ericsson be ultra cautious while definition you have to reverse Non Operating B table to Operating and Vice versa after changes. But before it non op need to be zeroed, if you do a zero command twice the whole B Table will get erased. Always backup the B Table and analysis tables on daily basis so incase of any recovery you will have latest backups in your local system.
E. Warnings and acknowledgements should be read carefully as sometimes such warnings and informations lead to a severe issue in the node.
There may be many more but we learn as we work on the systems daily. Let me know if you are stuck in somewhere in operations and maintenance and if you want more such topics should be covered in this blog. You can suggest via comments below, if you liked the article do share it in Twitter Facebook and Google plus.