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G700/S8300 Design, Is this normal? 3-G700/5-DS1's! 3

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Toni269

MIS
Apr 18, 2002
815
Looking at a vendor bid for an LSP S8300 G700 Design:

3 - G700's
5 - MM710 E1/T1 DS1 Boards (Customer has 5 T1's)
1 - EDGE SIP Server

I thought this was an odd design. When I checked with another BP I was told Avaya's recommendation is not more than 1 DS1 board per G700 but I wasn't able to find documentation on those types of limitations or recommendations.

This is for an 80 seat VoIP call center.

I was thinking that an 8500 ESS/IPSI and G650 would be a better fit. The link to the main site is MPLS, sites are 2,500 miles apart.

Thanks for any feedback!

Toni
 
The G350 can only have 1 MM710

We have a site with 2 G700s and 5 DS1 boards, 2 in one and 3 in the other and they work just fine. The primary G700 has an 8300, 1 - MM711 and 2 - MM710s. The secondary has 1 - MM711 and 3 - MM710s.

We also have a site that is 2,600 miles from the 8700 system using G700 with S8300 LSP and have no problems.

- Stinney

Favorite all too common vendor responses: "We've never seen this issue before." AND "No one's ever wanted to use it like that before.
 
The concern would be DSP resources. Depending on Codec you could be very limited. You have to figure with all VoIP phones you will be using atleast one if not more DSP for each and every call. There are 64 resources on the board, and with compression you drop to 32. With 2 T-1 in a single gateway you have 46 usable channels. SO lets just say you share resources between gateways with 5 T-1s you have 115 channels and with 2 gateways you have either 128 or 64 DSPs, with 3 gateways you 192 or 96 DSPs. In additon to this ASD will assume you could move calls from the T-1s acrross your MPLS to the HQ site.

 
This is great info. I also heard there is a limitation on the number of CLAN's you can add to this config?
 
Please note that you cannot share resources between media gateways. There is no common backplane. If you are using no compression (G.711) you can have up to 2 E1/T1 in one G700 unless you add a MM760 which provides you with another 64 DSP resources.
 
Toni268, CLANs are not used in MM gateways, only in G650's.

If you are talking about the MGC list, yes, that is limited to 4 entries. Typically you would have 3 CLANs, or 2 CLANs and perhaps PE (Processor Ethernet on an S8500) in the list... the 4th entry would be used for the local S8300LSP. You also need to set the MGP Recovery point to the number of CLANs/PE's.

Mitch
 
I'm not sure what compression they are setting up yet. So if ther eis no MM760 on this quote there's something missing in the design?

When you say you can't share resources, can all those T1's be in the same trunk group?

I'm still trying to figure out if this overall design is a good one that won't cause any problems.

Toni
 
Toni269, the VoIP Resourcecs built into each G700 (equivilant to 1 MM760), only serve the 4 MM slots in that particular gateway. They are not a "shared pool", similar to what you might find in a G650 with multile TN2302AP/or TN2602 Media cards.

Yes, the T1/PRI's can be in the same trunk group.

The issue is, if you use a compressed codec, such as G729, it takes 2 resources per channel/call. Being that the G700 only has 64 resources, you can only have 32 such calls up a the same time. With 2 PRI's or T1's, you in theory have 46 or 48 channels. Get it?

Mitch
 
Wow.....80 seat call center must be busy to require 5 DS1's. That is 118 channels if PRI w/2 D channels. If you truly need that many DS1's 3 g700's is probably the right number.

If you have that much traffic and do an g729 you could be short on DSP resources

We have a few site w/700, 110 IP sets, one gateway, 2 PRI's
and do not have DSP resource issues. But I think I'll look at traffic tomorrow :)
 
telecomturner, telnet into the MGC, and do a "show voip v0", this will show you how many "points" are in use at the current time, you will see there are a total of 1920 points.

I don't there there is a way to look at the history of the VoIP resources used, you just have to check it once in a while. If you know when your peak trunk usage is, that would be a good time to check the VoIP resources in each G700.

Mitch
 
Key issues here when planning.

1. Get a business partner that knows what he is doing, and can explain it to you.

2. The codec selection in this scenario is critical. As previously noted, Uncompressed G.711 allows for 64 resources on the G700 which use of a compressed codec such as G.729 will proportionatlely reduce the number of channels to 32. Example 20 users with G.711 and 20 users with G.729 - Resources used = (20)G.711 + (20x2)G.729 for a total of 60 out of 64 available in the G700. If all the agents are on the local LAN then I would recommed G.711. If your agents are at a remote site, off-site (at home agents) or you intend to have stations at a remote location at some point then you should assume day 1 that you will be using a compressed codec to the remote site.

3. From a long term planning standpoint and assuming that compression will be used, then you only can assume to have 32 resources per gateway. You can add an additonal MM760 to provide additional VoIP resources.

Here is what I would suggest if you agents will not all be on the local LAN.

G700-1
S8300
MM760
MM710
MM710

G700-2
S8300 LSP
MM760
MM710
MM710

G700-3
MM711 (Music-on-hold, paging, FAX, Modem)
MM710

Use partition routing and set any modem and FAX to go out a trunk group specifically set up on G700-3 as first choice to eliminate IP conversion if possible.



Jimbo
 
TT,
Going from G711 to G729 codec depends on the size of the pipe you will have between sites and the call quality you are trying to achieve. And like the man says no more than two MM710's per gateway. If you need someone to bounce ideas off of I can hook you up with my Avaya design guy here in Irvine.

Craig
 
Thanks Craig! If you can give me a call sometime, woulden't hurt for me to have another resource from Avaya.

Thank you everyone this feedbak has been awesome and much appreciated!
 
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