MGW ISDN channel status blocked & proposed state

[amitsalunkhe21]

Dear All

We are using PGW 2200 & MGW AS5400 for TDM termination from VOIP, I often observed on MGW many E1 channels in ei8ther blocked states or proposed  state.i have following question in regards to this

1. If E1 channels or ISDN channels in blocked or proposed state where is the issue

2. how we can rectify it & what we can fo avodi such state permanant basis

3 is there any relation between this 2 channel state and connectivity of PGW <--->MGW<-->PSTN operator g/w, any of this connectivity fluctuate can affect E1 channel state & then its blocked or porposed state.

Please help me.

Thanks

Amit--

[Muthurani Lavanya Paneerselvam]

Hi Amit

1. If your E1 channel or ISDN Channels are remains in blocked state even after the call is released check the,

a. CIC status on the PGW using mml > rtrv-cic ,

b. Then channel status on the MGW using # show voice call status

If there is any calls present on the # show voice call status , MGW and the CIC is utilized in the PGW then it is fine.

2. To rectify this blocked condition

Try resetting the CIC on the PGW and perform shut /no shut on the MGW to release the blocked channels/E1s. This will actually release your channels from being blocked.

Mml <>:CIC=[,RNG=]

If this scenario is repeating for long time, then you need check your MGW IOS and the PGW MGC application verision.

3. To answer your 3rd question, yes there are relations between teh PGW - MGW - PSTN operator on the connectivity.  Ensure your E1 is UP and the E1 is not fluctuating.

Thanks

[Dirk Christeaens]

If you notice there is a mismatch between the state of a CIC and its mated ISDN bearer, you can use the sta-aud

MML command to try and resolve the situation momentarily. If the situation happens frequently you will need to find the root cause by troubleshooting the issue and this often involves tracing/debugging the traffic on the CIC side (ISUP between PGW and PSTN) and the mated bearer (ISDN-like signalling between PGW and Voice gateway) as there is indeed a close relationship between some ISUP messages and Q.931+ messages that can affect CIC/bearer status. Also, IP connectivity issues can play a role as they can cause some of these messages to be missed. So, it is important to have stable IP links, and of course your E1 circuits should be running clean of errors as well.

[amitsalunkhe21]

HI Drik

Information your provided is very useful for me. But can you tell me in simple way where is the issue we can say if E1 channels are in Blocked or proposed state.

and

is there any relation between this 2 channel state and connectivity of PGW <--->MGW<-->PSTN operator g/w, any of this connectivity fluctuate can affect E1 channel state & then its blocked or porposed state.

Please help me