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  1. BGP Blackhole Users Guide
  2. Prefix Request Form
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  4. Internet2 Peerings - MTU Configuration
  5. Turning Off light on the ADVA optical shelf.
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  1. Turning Off light on the ADVA optical shelf.


"Jumbo" Frames and Internet2

Large IP frames, also called "jumbograms" or "jumboframes," have been recommended for high-performance networkslike Internet2 as a significant factor in increasing performance overlong distances. In general the limiting factor in frame size is theIP MTU (Media Transmission Unit, sometimes also called MaximumTransmission Unit), which by default on an Ethernet is 1500 bytes.The MTU is set independently for every interface in an IP flow'spath, and any interface can limit the size of the flow by fragmentingit. Path MTU discovery, described in RFC1191,attempts to discover the optimal MTU for the path to avoid fragmentation.

The Internet2 recommendation is to work toward an end-to-end IP MTU ofat least 9000 bytes today, and eventually much larger. Steps in thiseffort are:

  1. Set 9KB MTUs throughout the Internet2 backbone. This has been completed.
  2. Internet2 and its connectors work together to set 9KB MTUs where we peer with each other. See the table below for an indication of the progress of this effort.
  3. The Internet2 institutions set 9KB MTUs within their networks, at least to the high-performance end-stations.
    This page gives links to some of the reasoning for a large-frame recommendation, indicates some of the organizations and networks who have endorsed the concept and are working with us to increase MTUs, shows how it is done with Cisco and Juniper examples, and finally includes a list of all Internet2 connectors and peer networks and their current MTU status.

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it was last edited on 1 April2003
comments to Brent Sweeny,

Turning Off light on the ADVA optical shelf.

Keywords: ADVA, ADVA light, ADVA Tx light shutdown, Tx light turn off

For instances like Ledcor is on site testing fiber or Sunesys is workng on fibers they often request to shut the light on the fiber so that it does not interere with theit testing process. To turn off the Tx light on the ADVA code version 16.1.1 GUI here's what needs to be done (As given by ADVA support):

* NOTE: While this is the procedure for diabling the service signal the OSC channel ( OSCM in slot 3 most chassis) can not be turned off and will have to be removed to turn this light off Dispatch to each end of the segment is needed and removal fo the sfp facing the toward to the site  techs are trying to otdr is needed to remove light from the fiber.

1. Disable the port on the EDFA amplifier. 

EDFA slot -> Configure -> Ports -> Edit -> Disable

2. Disable the OSCM-PN port facing towards the other site where you want to disable the TX light. 

OSCM-PN slot -> Configure -> Ports -> edit -> Disabled.

Make sure to do the same (steps 1 and 2) for any Amplifier sites along the path. Please refer the faceplate diagram for that (Under backbone section in PennREN - NOC DOC)

3. Also make sure to admin disable the interfaces on the Junipers to avoid any alien waves on the backbone fibers that connect to the ADVA optical shelf. 

*NOTE : Please make sure to refer the Faceplate diagrams of the sites (Under backbone section in NOC DOC) to verify the correct card/ports before turning off anything.

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