MPLS TE max bandwidth

[Volodymyr Khrystenko]

Hello.

I have MPLS TE backbone core and all routers are connected with 100M links. But when I analyze OSPF base I get interesting result:

R6#sh ip ospf database opaque-area

            OSPF Router with ID (6.6.6.6) (Process ID 1)

                Type-10 Opaque Link Area Link States (Area 0)

  LS age: 1931

  Options: (No TOS-capability, DC)

  LS Type: Opaque Area Link

  Link State ID: 1.0.0.0

  Opaque Type: 1

  Opaque ID: 0

  Advertising Router: 1.1.1.1

  LS Seq Number: 80000003

  Checksum: 0x54D3

  Length: 28

  Fragment number : 0

    MPLS TE router ID : 1.1.1.1

    Number of Links : 0

  LS age: 988

  Options: (No TOS-capability, DC)

  LS Type: Opaque Area Link

  Link State ID: 1.0.0.0

  Opaque Type: 1

  Opaque ID: 0

  Advertising Router: 3.3.3.3

  LS Seq Number: 80000003

  Checksum: 0xD5C4

  Length: 132

  Fragment number : 0

    MPLS TE router ID : 3.3.3.3

    Link connected to Broadcast network

      Link ID : 192.168.5.1

      Interface Address : 192.168.5.2

      Admin Metric : 1

      Maximum bandwidth : 12500000

      Maximum reservable bandwidth : 9375000

      Number of Priority : 8

      Priority 0 : 9375000     Priority 1 : 9375000  

      Priority 2 : 9375000     Priority 3 : 9375000  

And such output is for all links. Default RSVP reservation line 75% is taken from 125M but not 100M. Please clarify why is it so. Thanks

[Volodymyr Khrystenko]

Hmm.

I think it is because the output is expressed in Bytes per second.

[Giuseppe Larosa]

Hello Volodymyr,

yes I agree

Hope to help

Giuseppe

[Harold Ritter · Accepted solution]

Hi Volodymyr,

This value is indeed expressed in bytes per second as per RFC3630 section 2.5.6:

2.5.6.  Maximum Bandwidth

   The Maximum Bandwidth sub-TLV specifies the maximum bandwidth that
   can be used on this link, in this direction (from the system
   originating the LSA to its neighbor), in IEEE floating point format.
   This is the true link capacity.  The units are bytes per second.

   The Maximum Bandwidth sub-TLV is TLV type 6, and is four octets in
   length.

For more information, please refer to the full RFC.

http://tools.ietf.org/html/rfc3630

Regards