SCN more than 5 hops error

[dwats9]

I have 7 IP Offices (500 v2 with 7.0.12 software with 7.0.19 Voicemail pro at the main site). As soon as I connect the 7th IP Office into the SCN, I get an error from all sites saying "more than 5 hops present. Each IP Office has an IP trunk going to all of the other schools (fully meshed network). Any help would be greatly appreciated.

Dan

 

[tlpeter]

What happens if you do not make a mesh but as a star (only for the 7th IPO)


BAZINGA!

I'm not insane, my mother had me tested!

 

[IPGuru]

by fully meshing the network you have exceeded the limits of the IPO
In a meshed SCN ther can only be a maximum of 5 routes to reach any host & you currently have 6 (see doc 15-601011 Issue 26.b)

the easiest solution is to reduce the number of links so you are only partially meshed.

with care it is possible to create a partial mesh that will still operate with a failure of any 2 links



Mundus vult decipi decipiatur ergo.

 

[dwats9]

If the SCN is not fully meshed, does it use voice networking licenses from each PBX it passes through?

 

[tlpeter]

No but you better use a star topology.
Like IPguru mentioned you could make a couple of mesh connections but further on it is not needed.


BAZINGA!

I'm not insane, my mother had me tested!

 

[kholladay]

@IPGuru can you post a link to this document? I want to read up on this limitation so we don't run into it.

Kyle Holladay / IPOfficeHelp.com
ACSS & APSS SME Communications
MCP/MCTS Exchange 2007
Adtran ATSA, Aruba ACMA

"I have one speed, I have one gear...GO!!!" - Charlie Sheen

"Thinking is the hardest work there is, which is the probable reason why so few engage in it." - Henry Ford

 

[Pepp77]

@IPGuru - me too as my understanding of the 5 hop limit wouldn't have the OPs setup (if I have read it correctly) as wrong, I say this because I have a customer with 9 sites on a fully meshed setup that works no problem.

To me the 5 hop rule means that you cannot go through more than 4 other systems to get to the destination system and in a fully meshed SCN each site would only be 1 hop away as they are in my 9 site setup?

| ACSS SME |

 

[kholladay]

@Pepp77 that was always my understanding as well.



Kyle Holladay / IPOfficeHelp.com
ACSS & APSS SME Communications
MCP/MCTS Exchange 2007
Adtran ATSA, Aruba ACMA

"I have one speed, I have one gear...GO!!!" - Charlie Sheen

"Thinking is the hardest work there is, which is the probable reason why so few engage in it." - Henry Ford

 

[dwats9]

@Pepp77 - You've read it correctly and that was my understanding also. In the fully meshed network, I was assuming that the longest route from Site 1 to Site 7 would be 6 hops, worst case scenario. But with a trunk between each system it should use that trunk and be only 1 hop.

Our SCN also functions perfectly, but in the SCN error list it shows the 5 hop error for each site.

 

[kholladay]

Interesting. I've never seen this error. What version? I've done several >10 location full mesh setups and have never seen it but perhaps I wasn't looking in the right place.

Kyle Holladay / IPOfficeHelp.com
ACSS & APSS SME Communications
MCP/MCTS Exchange 2007
Adtran ATSA, Aruba ACMA

"I have one speed, I have one gear...GO!!!" - Charlie Sheen

"Thinking is the hardest work there is, which is the probable reason why so few engage in it." - Henry Ford

 

[dwats9]

I'm using the latest 7 release, 7.0.12. If I open the SCN and then the error tab, it will have a dropdown on the error tab that lists each site and the SCN. On the SCN is where the errors are listed.

The fact that you have >10 fully meshed SCNs tells me this should function properly. This is our first SCN >5 IPOs and was hoping the error was a glitch since our SCN seems to function without a problem.

 

[kholladay]

There are often errors reported that are either not true or do not impact the system. I believe, personally, you can ignore this.

Kyle Holladay / IPOfficeHelp.com
ACSS & APSS SME Communications
MCP/MCTS Exchange 2007
Adtran ATSA, Aruba ACMA

"I have one speed, I have one gear...GO!!!" - Charlie Sheen

"Thinking is the hardest work there is, which is the probable reason why so few engage in it." - Henry Ford

 

[Pepp77]

Definitely ignore that error - I have just checked my 10 system site and I get the same - I think because the system looks at the worst case scenario and then gives an error even though there are much better routes the system would try first.


| ACSS SME |

 

[dwats9]

Thanks for the info. I received this email from Avaya R&D through our distributor:

“they have to design the network so there is no more than 5 hops in any direction”

“the 5 hop limitation assumes you are planning the network and not just adding lines”

“our software will not think for them”

“the number of systems is not important, the layout and configuration is, yes no more than 5 hops in any direction to get to another system /any of them”

“our Viewer Mesh is not a true full mesh-able network, we still have limitations”

“I would recommend that they plan it out first before just adding lines”


IMO, this suggests that we cannot make a fully meshed network over 6 IPOs. I would love to hear what others think since you have successful fully meshed SCNs deployed that are >6 IPOs. Has anyone run into any problems/limitations with the meshed setup?

 

[IPGuru]

The quoted doc is on the documents disk, I do not think it is teribly well written & I have made a number of assumptions.

I think this is failing be cause the maximum number of hops a call could take (not necessarily the direct route) is greater than 5, in theory a call from site 1 to site 2 could go through all the other sites first if certain links were to fail.

I may be wrong on this but it seams reasonable otherwise the memory overhead in keeping track of the ways to each possible switch would soon become unmanageable).

Following the principle or kiss (Keep It Simple Stupid)I would configure SCN's with a star topology (or possibly connected stars) with 1 or 2 extra links form each site to ensure redundancy in case of a link failure




Mundus vult decipi decipiatur ergo.

 

[tlpeter]

IPGuru is right.

Let the routers do the routing and keep it simple.



BAZINGA!

I'm not insane, my mother had me tested!