I am not an expert! -Problem

Unanswered Question
Jul 30th, 2008

Our network is part of Verizon ATM Cloud - we have two remotes sites that work great they do not drop pings(1000 bytes) They each run on 1.5 ATM. At the Main site we have a DS3 10mb. that the two remotes come into. We also have going out 6mb PVC to out ISP. When we ping our ISP 1000(bytes)size or more we drop packets. Verizon already test the circuits (remotes sites) and my main circuit that goes into the ATm cloud. the ISP circuit that goes into the cloud did not get tested.because they have other customers on it. I feel like Verizon did everything they could. what should I do!?

I have this problem too.
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m-haddad Wed, 07/30/2008 - 15:15

Some ISPs implement a policy to drop ICMP packets larger than certain size. Also, some firwalls drop ICMP packets greater than certain packet size. Are you trying to ping the next hop on the 6Mbps PVC? Try to check with the ISP if they have this type of policy or if there is a firewall on the ISP sites (Which I doubt) dropping traffic.


jleipert79 Wed, 07/30/2008 - 16:00

Yes- it's the next hop(ISP router) I was on the phone with them with the Verizon tech - The ISP tech did see the drops when he pinged my side. The ISP did not want to to test there DS3 circuit (pvc)because of other customers. he also checked out other settings and said everything looked ok. He also said that the router(isp router) was not picking up any errors. We also created a new PVC (assigned new vpi /vci) (i think i'm saying that write) And the errors were still there. Who should I start questioning verizon or isp.

Also my upload speeds are fast like 4.5mb and my download speed are slow 600k. wierd to me?

thanks again

m-haddad Thu, 07/31/2008 - 07:55


Since your ISP circuit is another PBC as you are stating then you should just test the ISP link from the main site. Verizon have no issues since they only provide WAN connectivity between sites. As I understood the PVC you have with the ISP is a shared PVC? So is this PVC congested? This is something to ask the ISP.

Another thing you can try, can you put a laptop on the outside zone and set it with public IP Address and do some testing? This will isolate the issue to be on the outside or not.

Let me know how it goes,


jleipert79 Thu, 07/31/2008 - 14:19

what does PBC stand for ...sorry :)

yes the PVC is shared..what's funny too is that other schools that use the same ISP are having the same problem. i did put a pc on the outside problem still there..

This was the last email from the verizon tech


Hope this is working for you. I would think that the service that they

are providing you right now is not sound and does not perform to what it

is supposed to you should be able to have packets over a 500 datagram

that do not drop packets. I am not sure why snip will not try and work

with VZ and fix the issue. There are seeing the issue when pinging your

interface on the router but can not do anything about it? I question


m-haddad Thu, 07/31/2008 - 14:29

Sorry it was typo mistake I meant PVC and not PBC.

One way to get through this, since the ISP engineer is no more helpfull, is to contact your ISP sales/account manager. Try to explain to him the poort support on this and threaten you may think of other options and search for another ISP.

Most of the time when you touch the money side of things the support improves and they do their best to resolve it. :-)

Sorry couldn't resolve your issue but all I can see is that your ISP has to do more effort to resolve the issue.


- Sometimes ISPs know that they have an issue and try avoiding informing the customer trying to gain some time until they resolve it.


jleipert79 Thu, 07/31/2008 - 14:46

thanks for all your help! It's nice to bounce things off - it makes me not soo crazy :)

I have my boss writing a letter to the CEO

soo well see.

thanks again



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