Wan with a difference ?

[andydis]

Is it normal for a company with remote sites to have all remote sites with 2 routers ?

1 for VoIP and 1 for data ?

 

 

Most have fibre but then strangely they have 2 drayteks attached 1 for data and 1 for data .

 

( I am assuming anyway , I need to do an audit before I check they may be on seperate broadbands )

 

Surely they should have 1 good router with qos at each site ?

[FN-GM]

There could be more a political reason than a technical reason. Setup correctly though I cannot see why you would need 2. Unless they are setup with high availability and using something like GLBP.

[andydis]

no they are not highly available

[Sagima]

I take it you don't have two separate physical networks to go along with them put in by someone who couldn't get to grips with vlans?

Seems unnecessary - I'd replace them with the one when the time came along to do so but probably wouldn't do it without a good reason if it's otherwise working fine. Wouldn't put two in any new sites.

[andydis]

someone who couldn't get to grips with vlans

 

think you hit the nail on the head here.

[GeekyPete]

Not Normal. They went for a rather un-sophisticated method of segregation. It could be due to bandwidth if each router has it's own line. If not it can all be done with VLANs and QoS settings but that would need someone who knows what they are doing.

[Opendium_Steve]

I've seen this a few times and think it's nuts - especially on sites which have a few hundred megabit internet connections who are running their phones over an ADSL! Often it's rigged so that the ADSL provides a nice big security hole that bypasses all the firewalling to the main network too. I suspect it comes down to the phone system suppliers not wanting to get involved with the existing network (I'm afraid I've seen a few phone system installers who simply don't understand IP routing at all - presumably people who were in the phone business long before VoIP happened who still haven't caught up)

[andydis]

Thanks Steve , upon further investigation (its a right mess) , most remote sites have 2 Fibre ADSL lines in with a draytek attached to each.

 

looks like all the PC's are going via 1 ADSL and the VOIP via another, however i have noticed they have MPOA LLC enabled as attached, does anybody have experience with what this is?

 

[Opendium_Steve]

Thanks Steve , upon further investigation (its a right mess) , most remote sites have 2 Fibre ADSL lines in with a draytek attached to each.

 

looks like all the PC's are going via 1 ADSL and the VOIP via another, however i have noticed they have MPOA LLC enabled as attached, does anybody have experience with what this is?

 

[ATTACH=CONFIG]31924[/ATTACH]

 

Usually you'd have a PPP connection to the ISP - the endpoint of the PPP connection is responsible for routing IP traffic to/from the ISP, so it is the default route for your network. The PPP endpoint can be the DSL modem itself - in which case the modem is doing "PPP over ATM" (PPPoA). Or the PPP endpoint could be some other piece of equipment on your network - in which case the modem will be set to be a bridge (which just blindly forwards ethernet packets between the ADSL and the network) and another device will be doing "PPP over Ethernet" (PPPoE). There are other possible configurations, but I'm not aware of any ISP providing them in the UK - for example, Danish ISPs often don't use PPP at all.

 

It looks like that router has two connections configured on it: VCI 38 with PPPoA and VCI 101 is bridged straight to the network (so possibly expecting another device on the network to be a PPPoE endpoint). Might be worth checking with the ISP and VoIP supplier whether both VCIs are correct - I've never seen a setup with multiple VCIs configured so one of them might be redundant. (VCIs are similar to VLANs, allowing multiple separate connections to be sent along a single DSL).

[SchoolsBroadband]

Quite often if you move your voice and data to a single broadband line with a low SLA (which standard broadband is) customers perceive that broadband is not as reliable as PSTN or ISDN so they ask the question "what happens if my Internet connection goes down?" the fact tis they'd lost both voice and data.

 

We could get into many arguments of the fact that copper pairs are normally routed to a building the same way anyway so if there was an issue with a single PSTN line then it would probably effect them all and this to an extent is true. However one more common problem we've seen with other ISP's is that they actually have core outages or an LLU provider does. So if you use 2 separate ISP's and those ISP's also are different LLU providers (or one LLU and one BT Wholesale) then the chances of both of their equipment failing at the phone exchange at the same time is substantially less.

 

The good thing of if you do have 2 x lines from different ISP's with VoIP is that if one does have an issue then you can often move all traffic onto the other line an utilise QOS. At the end of the day its down to the end customer if they wish to pay extra for an additional line to mitigate risk.

 

Finally remember normal broadband as standard does not come with any network level QOS, where as some LLU providers (or via leased lines) can do end to end QOS and guarantee VoIP latency, jitter and packetloss so if their softswitch / PBX is on their own network then they can guarantee the VoIP call all the way back to it, where as if you put a broadband in from one provider and use a VoIP provider which has its equipment located somewhere on the Internet then even though you can do local QOS the packets have to travel over the general Internet and there is no guarantee it will get there, the bandwidth will be available or there will be no issues.

 

Just my 2p.

 

Dave