The MPLS-OPS Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] RE: Circuit Emulation using MPLS?
Mathew, Many thanks for you articulate response. We don't actually have a network yet. The design is in place and we are expected to start building in Q1'02. Currently waiting for funding to close. We do offer contended IP (Data) services over the network and the CES stuff is only expected to equate to 10-15% of total product. However, it will probably equate to 30-40% of total margin!!! I was actually one of the first in Europe to implement MPLS in a previous company and so do believe in it and continue to look at MPLS as an alternative before we start building. But, it is not cost effective to build two side-by-side networks and we need to have CES (more due to market understanding "I want an E1" than anything else) so, unless the draft spec. I mentioned pans out, it looks very much like I am going ATM only for a while! Thanks to all who contributed David -----Original Message----- From: Mathew Lodge [mailto:mathew@cplane.com] Sent: 11 December 2001 16:31 To: Young, David J Subject: RE: Circuit Emulation using MPLS? David, For your situation, the simplest option is to continue offering point-to-point E1s via ATM circuit emulation. It works, you already have the network in place... no need to foul up a perfectly good service by "improving" it :-) However, the problem with a network full of emulated circuits is that it doesn't make very efficient use of the network resources. You can get a better rate of return on your network if you offer data services that can be oversubscribed. Think of good old circuit emulation as the simplest, most widely applicable service -- but also the least efficient. An oversubscribed network is more capital efficient because you can oversubscribe network resources, say, 10:1, but charge (say) 1/5th of the price of guaranteed bandwidth and pocket the difference. With dedicated, guaranteed bandwidth (circuit emulation) there can be no oversubscription. Given that you already have an ATM network, you could offer oversubscribed point-to-point ABR data service to improve ROI. Your customers then become self-selecting based on price: they can simply buy an E1 and know they get guaranteed bandwidth, or pay less money but know they're getting a data-only beft effort service. And, of course, you can do frame-like CIR plus burst guarantees for some price in between guaranteed and best effort. However, whether or not you can sell this does depend on your customer base -- as typically the end customers for ATM are large corporations and they use ATM for inter-city or inter-continental connectivity. You might want to look at MPLS as a way of expanding the number of data services that you can offer. Most vendors are supporting point-to-point Ethernet over MPLS, and this is a more attractive solution to many end customers because the end customer connectivity and CPE requirements are less onerous than ATM. With the right service activation software, you can also give end customers real-time control over their bandwidth, even in a wholesale environment (OK, enough about what CPLANE does :-). MPLS also offers the ability to do full IP VPNs as well as point-to-point IP links. The complexity of such a service is much higher than ATM or Ethernet over MPLS, but it scales better for large networks. Regards, Mathew At 09:43 AM 12/11/2001 +0000, Young, David J wrote: >Thanks to all who commented on this subject. My main issue is more of a >business issue than technical in than we are an wholesale only "Access >Service Provider" and do not sell solutions direct to customers. Therefore >we do not often get involved in changing the customers network design (i.e. >putting in Media gateways, etc.). We currently have an ATM network and >offer two main product types... > >1. IP >2. TDM > >With TDM, we do Circuit Emulation as it is much easier for us to just say >"Here is an E1 pipe, use it for whatever you want". > >I have just found a proposed internet draft >[draft-malis-sonet-ces-mpls-05.txt]. I have not read it though yet but >would be interested in any industry views on this draft or any other >potential solutions. > >Many thanks, > >David Young > >-----Original Message----- >From: Mathew Lodge [mailto:mathew@cplane.com] >Sent: 10 December 2001 20:54 >To: Santiago Alvarez; raszuk@cisco.com >Cc: Young, David J; 'mpls-ops@mplsrc.com'; saalvare@cisco.com >Subject: Re: Circuit Emulation using MPLS? > > >At 01:17 PM 12/7/2001 -0800, Santiago Alvarez wrote: > >Let me add some comments. You're effectively providing circuit emulation > >when you trunk voice through an IP/MPLS network. In this case, it's > >really the voice gateway the one that compensates for the jitter and > >possible loss introduced by the network. As Robert mentioned, the apps > >are been built to connect to the IP/MPLS network and take care of the > >emulation. I guess if you consider the case of a network with edge LSRs > >also acting as voice gateways, you could argue that your MPLS network is > >providing circuit emulation (at least for your voice services) ;-) > >While this is true, there are a lot of non-voice services carried over >voice bearers today that make this an unusable solution for a carrier-class >network. Good examples are modem and fax traffic. While both of these can >be jitter buffered, treating them "just like voice" (e.g. by sticking the >TDM frame into an RTP packet and crossing your fingers) doesn't work. The >problem in real networks is packet loss. Even very small amounts of packet >loss on the path (less than 1%) will cause fax and modem calls to fail when >carried as VoIP. And real networks have enough packet loss to lead to major >drops in call success rate for fax and modem calls. > >So, what this really means is that it is a combination of a well engineered >MPLS network and a good IP media gateway that is required to match ATM >circuit emulation. The MPLS network has to offer guaranteed bandwidth >(which, by the way, is entirely possible using policing and marking at the >edge (i.e. int-serv) mapping to coarse grained diff-serv in the core). The >media gateway has to take care of jitter buffering and encoding for voice, >fax, modem and any other non-voice traffic carried over voice-like bearers. > >Regards, > >Mathew > > > >SA > >-- > > > >Robert Raszuk wrote: > > > > > > I think that providing circuit emulation over IP or MPLS/IP networks > > > should be simply forgotten. If ATM remains alive it is for this very > > > application. To really provide this over IP you would need to use RSVP's > > > int serv model what as you know never scaled to the production > > > capacities of any service provider. > > > > > > With L2 transport or with L3 routing you can achive achive almost the > > > same set of applications VoIP, videoconferecing etc, trunking what you > > > would use circuit emulation but this is different - those new end > > > systems and applications are desiged to work over IP networks. > > > > > > Old fashined devices desined to use circuit emulation are not. > > > > > > Also you should not be mistaken about differences of carrying ATM cell > > > payload of AAL5 mostly used for data communication over IP/MPLS networks > > > and trying to carry in the same way AAL1 (circuit emulation ATM > > > adaptation layer). > > > > > > Rgs, > > > R. > > > > > > > "Young, David J" wrote: > > > > > > > > Can anyone please post any detail relating to comparison of ATM >Circuit > > > > Emulation Services, Vs capabilities with MPLS to achieve similar >results. > > > > > > > > Many thanks, > > > > > > > > David J Young > > > > Manager, Voice & Data Services > > > > > > > > Bulldog Communications Ltd > > > > Golden Cross House > > > > 8 Duncannon Street > > > > Strand > > > > London, WC2N 4JF > > > > > > > > Direct line: 020 7484 5644 > > > > Direct Fax: 020 7484 8701 > > > > Mobile No.: 07767 793636 > > > > E-Mail: davidjyoung@bulldogcommunications.com > > > > www.bulldogcommunications.com > > > > > > > > ********************************************************************** > > > > This email and any files transmitted with it are confidential and > > > > intended solely for the use of the individual or entity to whom they > > > > are addressed. If you have received this email in error please notify > > > > the system manager. > > > > > > > > This footnote also confirms that this email message has been swept by > > > > MIMEsweeper for the presence of computer viruses. > > > > > > > > www.mimesweeper.com > > > > ********************************************************************** > > > > Bulldog Communications Limited is registered in England, number >4005262, > > > > with its office address at Golden Cross House, 8 Duncannon Street > > > > LONDON, WC2N 4JF, United Kingdom > > > > > > > > ------- > > > > The MPLS-OPS Mailing List > > > > Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml > > > > Archive: http://www.mplsrc.com/mpls-ops_archive.shtml > > > > > > ------- > > > The MPLS-OPS Mailing List > > > Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml > > > Archive: http://www.mplsrc.com/mpls-ops_archive.shtml > > > >-- > >----------------------------------------------------------------------- > > Santiago Alvarez (408)527-9285 : : > > IOS Technical Marketing - MPLS/QoS santiago@cisco.com ..:::..:::.. > >----------------------------------------------------------------------- > > > >------- > >The MPLS-OPS Mailing List > >Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml > >Archive: http://www.mplsrc.com/mpls-ops_archive.shtml > >| Mathew Lodge | mathew@cplane.com | >| Director, Product Marketing | Ph: +1 408 789 4068 | >| CPLANE, Inc. | http://www.cplane.com | > > >********************************************************************** >This email and any files transmitted with it are confidential and >intended solely for the use of the individual or entity to whom they >are addressed. If you have received this email in error please notify >the system manager. > >This footnote also confirms that this email message has been swept by >MIMEsweeper for the presence of computer viruses. > >www.mimesweeper.com >********************************************************************** >Bulldog Communications Limited is registered in England, number 4005262, >with its office address at Golden Cross House, 8 Duncannon Street >LONDON, WC2N 4JF, United Kingdom | Mathew Lodge | mathew@cplane.com | | Director, Product Marketing | Ph: +1 408 789 4068 | | CPLANE, Inc. | http://www.cplane.com | ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com ********************************************************************** Bulldog Communications Limited is registered in England, number 4005262, with its office address at Golden Cross House, 8 Duncannon Street LONDON, WC2N 4JF, United Kingdom ------- The MPLS-OPS Mailing List Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml Archive: http://www.mplsrc.com/mpls-ops_archive.shtml |
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