HI I am a newbie to Geekzone, but have read many people complaining about their broadband ISPs. I have recently moved back from Sydney and was using a wireless service UNWIRED, and now on WOOSH. Don't see what all the big fuss is about with signing up with ADSL. I am happy with being wireless, not needing to have landline, and the speed with WOOSH is fine for what I do.... i am not into online gaming and the W price is good. So for you all out there getting bad service, give WOOSH ago. Best of all you can change your plan in the My Account section and it will happen! .... that should fix your Orcon plan change problem, if you are lucky enough to be in the Woosh zone.
PPP,L2TP,UDP,IP,ATM,SDH *shrug* crappy efficiency for small PDUs whatever way you look at it. Slightly better with GigE given you only have QnQ inside MPLS and your layer one overhead.
Ignoring the well-known inefficiency of ATM due to the 48-byte cell, using Ethernet for UBS isn't all that much more efficient. You replace the ATM overhead with Ethernet and it's overheads, 802.1Q, and potentially as you point out an outer 802.1Q tag. If you're transporting this over a metro-E platform using VPLS, you have to include the MPLS overhead as well. You haven't replaced the other protocols in the stack, as you have pointed out.
It is actually possible to make Ethernet just as inefficient as a transport protocol as ATM - I have some circuits that have 11% overhead due to protocol stacking. Transporting ATM over MPLS/IP becomes even more hysterical, though we're going really far off-topic.
The obvious advantage to Ethernet for ISPs is the cheaper interface cost (although not always strictly true, especially when looking at Juniper PICs) and the increased bandwidth. The flip side is that it's harder to get *fast* redundancy (no APS) without SDH, or using extremely RSTP which introduces another set of headaches.
The obvious advantage to Ethernet for ISPs is the cheaper interface cost (although not always strictly true, especially when looking at Juniper PICs) and the increased bandwidth. The flip side is that it's harder to get *fast* redundancy (no APS) without SDH, or using extremely RSTP which introduces another set of headaches.
Hmm sub 25ms for MPLS itself, STP is slow though yes.
Also Jumbo frame support is nice for WANs.
PenultimateHop: It is actually possible to make Ethernet just as inefficient as a transport protocol as ATM
Sure but thats true of any data layer. You pick and implement whats appropriate based on what your transporting, amongst the myriad of other requirements and trade offs. There is quite a bit of ATM stigma is seems, while some of it is deserved it does has its place. I mean for CBR services for instance its arguably technically superior
Fraktul: Hmm sub 25ms for MPLS itself, STP is slow though yes.
Also Jumbo frame support is nice for WANs.
MPLS Fast Re-Route is generally more in the 40-60msec region, rather than 25ms, in order to match SDH with ~50ms.
Unless you're deploying MPLS all the way to the Access Seeker premises, how does it help you? It's useful in your core network and in your Metro-E platform, but you still have the problem of needing to get that resiliency into the Access Seeker's network. I realise that B2B MPLS is currently being discussed in the MPLS Forum, but it's still a ways off being standardised.
This leaves you with RSTP; or other mechanisms (eg. LAG emulating APS, or Juniper's pseudo APS for Ethernet) that don't quite meet those idyllic goals for being able to reliably transport voice. Obviously there are ways around it, but it is still one area that ATM has an advantage.
Fraktul: Sure but thats true of any data layer. You pick and implement whats appropriate based on what your transporting, amongst the myriad of other requirements and trade offs. There is quite a bit of ATM stigma is seems, while some of it is deserved it does has its place. I mean for CBR services for instance its arguably technically superior
Anyhow I digress, getting off topic!
Certainly getting off topic but an interesting chat anyway... I do agree w.r.t stigma. It also amuses me to no end that MPLS, Ethernet, and IP are being used to try and re-implement what ATM has done since day 1: Support multiple class of service on a single interface, and support it well. I think ATM's true power is beyond CBR services and actually in the other grades of service, and in particular being able to support discard eligibility for traffic. This is a very powerful function, particularly in designing residential broadband services.
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