6513/sup 720 vs router 7200

Discussion in 'Cisco' started by inge network, Nov 15, 2003.

  1. inge network

    inge network Guest


    Over a SDH/SONET MAN network, why keep using a router 7200 instead of a
    6513/Sup720 ?

    I think that, a 6513 with CEF and Layer 3 routing/switching is much more
    efficient connecting directly to giga ethernet link.

    what do you think about it ?

    inge network, Nov 15, 2003
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  2. If the sup720 support all the features you need, it's a much more
    powerfull platform than the 7200
    Jesper Skriver, Nov 15, 2003
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  3. inge network

    Steinar Haug Guest

    ["inge network"]

    | Over a SDH/SONET MAN network, why keep using a router 7200 instead of a
    | 6513/Sup720 ?
    | I think that, a 6513 with CEF and Layer 3 routing/switching is much more
    | efficient connecting directly to giga ethernet link.

    Depends entirely on what you want to do. The 6500 does hardware routing/
    switching, and can obviously handle much higher bandwidth/packet rates
    than a 7200. On the other hand, it is also much more expensive.

    Steinar Haug, Nethelp consulting,
    Steinar Haug, Nov 15, 2003
  4. inge network

    inge network Guest

    Our interface with the ADM (SDH) can be in ethernet gigabit, so it's cool.
    We use SMHD (FT offer).

    In fact, we have two options :
    1) Use SMHD (FT), with Gigabit ethernet Interface, to have 622 Mb/S
    2) Use DWDM to have 1Gb/s up to 80 Gb/s. (much more expensive, but
    scalable...very efficient).
    we can have a n-ethernet gigabit interface.
    but, perhaps directly in DWDM ??
    Do you know the caracteristics of the DWDM interface of Sup 720 ?

    inge network, Nov 15, 2003
  5. You misunderstand, I bet option 2 is for a DWDM channel, which is
    transparent to the payload, and support up to a given bit rate (which I
    bet is lower than 80 Gbps, most likely 2.5 or 10 Gbps).

    This means that you can send any signal up to that appropiate bitrate
    through the WDM channel, all you need to ensure is the optical
    interface, wavelength and signal strength.

    So you could use it for 1 Gbps ethernet today, and switch to 10
    Gbps ethernet when you have the need, given the WDM transponder
    support that bitrate.

    But as your current need can be handled with a 7200, it would be
    wast overkill to go for the WDM transponder solution, especially
    as it's likely that the options are different the day you need
    more bandwidth.
    Jesper Skriver, Nov 15, 2003
  6. inge network

    inge network Guest

    Yes... I don't know very well dwdm.
    that's mean, it don't care about the protocol, because it is only a muliplex
    of optic wavelength ?
    Yes, I was very amazing, but it is what the commercial has told me, perhaps
    in the future ?
    Ok for this.
    how to ensure ?

    How can I be sure that the WDM transponder supports the bitrate ?
    Several dozens of stations of a site A have to send frequently severals
    hundred of Mo over
    our man network via NFS/udp...to a site B where is the nfs server.

    The stations are over 100F switch on the access layer, then theirs switchs
    are connected
    to distribution layer with etherchannel gigabit and then to the core
    (6513...sup 720 (recently)) layer by etherchannel gigabit.

    But nowadays, the core is still only connected to the 7200 in fastethernet
    and then over a 155 mb/s SDH which
    connect the site B by a 7200 too.

    => 7200 queue congestion !!
    => nfs//udp => oops :eek:) => we decide to use nfs/tcp.

    but we want too, to use directly our 6513, because we have it, and upgrade
    our wan link to gigabit.

    what do you think about it ?
    inge network, Nov 15, 2003
  7. No, a WDM transponder is a wavelength adaption.
    There will likely be equipment that can do 80 Gbps per channel in
    the future, but it would most likely require the service provider
    to replace all the kit.
    Ask the service provider for the specifications, or ask if it will work
    together with the interface you intend to use, you will have to supply
    them with the wavelength, transmit power and recieve sensitivity.
    Ask the provider if it works with 10 Gbps ethernet.
    That will most likely help, but if what you get from the provider is a
    622 Mbps link with GigE interfaces, you will have to apply queuing on
    your GigE interface down to 622 Mbps if you do not want the provider to
    choose which packets to drop when congestion occour.

    And given you upgrade from 155 Mbps, 10 Gbps Ethernet is likely
    wast overkill.
    Jesper Skriver, Nov 15, 2003
  8. inge network

    inge network Guest

    Arf, I hope it will not be this...but DWDM = $$ , even if with 1 or 2 gb/s
    what about the 6513/720 and queuing ? do you implement it ?
    feedback ?

    Otherwise, do you think I have to tune tcp and socket on my stations and
    server ?

    Do you have already use JumboFrame ? (I don't know the mtu of SDH...)
    Yes, I agree. I think a DWDM with 1 gbs or 2 Gbs would be a good thing.

    Imagine this scenario :
    I have 50 stations (on 4506) which have to trasmit 600 Mo at the sametime
    (or nearly) over 100F.
    the 4506 is connected to 6513 with N1-gigabit etherchannel.
    Imagine I have a wan link N2-giga connected to a 6513 connected to my NFS
    suppose server respond immediatly (no problem on it).
    idem for the stations.

    How can I calculate N1 and N2 and correlate it with the duration of
    exchange ?
    for one station and for all.
    (No jumbo frame. No QoS.)
    Suppose : nfs / udp.
    my idea : I have the mtu 1500 bytes => i calculate the number of datagramme.
    delay propagation : c / 50 km.
    first delay transmission : 1500 / 100 000 000 s * nbre of datagram
    then samething for giga link and wan.
    delay queue : suppose 0.
    delay proc : ??

    Arf...Too hard ! :eek:)

    A idea ?

    inge network, Nov 15, 2003
  9. As a WDM channel cost the same for the provider if you use it for 10
    Mbps or 10 Gbps, I would expect it to cost roughly the same, you might
    be able to get a 2.5 Gbps channel cheaper than a 10 Gbps channel though.
    I do not use any cat6k's so I cannot comment on this.
    If you expect to transfer anything like 1 Gbps over a single TCP
    connection, yes, you for sure will have to do so.
    If you use the WDM solution, there is no SDH involved.

    If you go for the SDH solution with GigE interface, verify with the
    provider the max MTU they support.
    If you go for the WDM solution, instead of the 622 Mbps with GigE
    interfaces, the only difference in cost between 1 and 10 Gbps will be
    your interface, if the provider provide you with a WDM channel capable
    of 10 Gbps.
    How do you imagine you will get two or more 1 Gbps ethernet connections
    over one WDM channel ? You cannot unless you have something to multiplex
    Nothing responds immidiately.
    Jesper Skriver, Nov 16, 2003
  10. inge network

    inge network Guest

    Ok, I think I will try 622 with GigE interface with queuing on a 6513.
    inge network, Nov 16, 2003
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