MPLS TE bandwidth questions

RSVP-TE carry the bandwidth information

2 - What's the difference or meaning between the following terms (an example could be useful):

    a) Max-link-bandwidth------->I didn't find this command, would you please clarify where did you find it?

    b) Max-reservable-bandwidth------>Means the max bandwidth for MPLS TE tunnel

    c) Max-available-bandwidth------>I didn't find this command, would you please clarify where did you find it?

    d) "mpls te bandwidth bc0" command----->Means the max total bandwidth for CT(class type) 0.

Hi everyone,

About question 1)

1 - Who carry the bandwidth information, the IGP or RSVP-TE?

From HedEx:

Information advertisement: Extends an IGP to advertise TE information, in addition to routing information. TE information includes the maximum link bandwidth, maximum reservable bandwidth, reserved bandwidth, and link colors.

Every node collects TE information about all nodes in a local area and generates a traffic engineering database (TEDB).

RSVP-TE Overview
The Resource Reservation Protocol (RSVP) is designed for the integrated service model and used on each node along a path for resource reservation. The bandwidth reservation capability makes it a suitable signaling protocol for establishing an MPLS TE tunnel.

RSVP-TE is an extension of RSVP to meet MPLS TE requirements. RSVP-TE extends RSVP in the following aspects:
RSVP-TE appends Label Request objects to Path messages to request labels. Resv messages carry Label objects that are used to allocate labels.

The extended RSVP messages can carry information about path constraint parameters, in addition to label binding information.

RSVP-TE provides the resource reservation function by supporting MPLS TE bandwidth constraints through the extended objects.

So it seems the IGP carries the bandwidth information and RSVP-TE reserves the resources along a path. RSVP-TE carries information about path constraint, but from HedEx --> Path constraint: includes the explicit path, priority and preemption, route pinning, affinity attribute, and hop limit. It seems bandwidth isn't a path constraint so RSVP-TE doesn't carry bandwidth information.

Am I right?

Julián

Hi all,

It is not a command, it is a term. Anyways, there is this command:

mpls te bandwidth max-reservable-bandwidth bw-value (kbit/s)

c) Max-available-bandwidth------>I didn't find this command, would you please clarify where did you find it?

It is not a command, it is a term. From the HCDP-BITN: The MPLS TE tunnel supports eight tunnel priority levels, namely, 0-7. The tunnels with different priority levels support preemption. The maximum available bandwidth for each priority can be specifid for each interface.

For instance, for our customer, I can find this two commands in every physical interface along a TE tunnel:

What's the meaning?

Best regards,

Julián

Hi dears,

¿Any update?

Regards,

Julián

Hi Dear,

1 - Who carry the bandwidth information, the IGP or RSVP-TE?
OSPF or ISIS with TE extension carry status information of link, max bandwidth, etc.

RSVP-TE is a signaling protocol to reserve resource, this is in charge to send path msg with a request label and ERO(explixith route object) to dowstream NE and sedn resv to confirm reservation, allocating the label mpls.

2 - What's the difference or meaning between the following terms (an example could be useful):

   a) Max-link-bandwidth

    i think this command doesnt exist

   b) Max-reservable-bandwidth

    Look the following relation, in a Gig interface you can set the BW to be reserved by tunnels as maximun if you reach this maximun no new tunnels can be set up(except a tunnel with better priority of currents).

     CT0≤BC0≤max-reservable-bandwidth

   c) Max-available-bandwidth

     i think this command doesnt exist

   d) "mpls te bandwidth bc0" command

        this is the bandwidth for global BC0, actually you can set for BC0, BC1 to BC7 each one define differentes priority and this is mapped with CT0, CT1, .., CT7.

example:

I configured bc0 100 000 and bc1 10 000 Kbps you can see in display that i have CT0 and CT1 using this values.

take care that inside each BC we have the tunnel priority 0-7 so BC is not same the setup/hold priority.

interface GigabitEthernet0/0/2

 ip address 10.10.10.9 255.255.255.252 

 mpls

 mpls te

 mpls te bandwidth max-reservable-bandwidth 100000

 mpls te bandwidth bc0 100000 bc1 10000

 mpls rsvp-te

#

  Link ID:  GigabitEthernet0/0/2

  Bandwidth Constraint Model   :  RDM

  Maximum Link Reservable Bandwidth(Kbits/sec):  100000

  Reservable Bandwidth BC0(Kbits/sec)         :  100000 

  Reservable Bandwidth BC1(Kbits/sec)         :  10000 

  Downstream Bandwidth (Kbits/sec)           :  0

  IPUpdown Link Status                       :  UP

  PhysicalUpdown Link Status                 :  UP

  GracefulUpdown Link Status                 :  DOWN

  ----------------------------------------------------------------------

  TE-CLASS  CT    PRIORITY   BW RESERVED   BW AVAILABLE   DOWNSTREAM

                             (Kbit/sec)     (Kbit/sec) RSVPLSPNODE COUNT

  ----------------------------------------------------------------------

     0      0        0           0             100000           0

     1      0        1           0             100000           0

     2      0        2           0             100000           0

     3      0        3           0             100000           0

     4      0        4           0             100000           0

     5      0        5           0             100000           0

     6      0        6           0             100000           0

     7      0        7           0             100000           0

     8      1        0           0             10000            0

     9      1        1           0             10000            0

     10     1        2           0             10000            0

     11     1        3           0             10000            0

     12     1        4           0             10000            0

     13     1        5           0             10000            0

     14     1        6           0             10000            0

     15     1        7           0             10000            0

  ----------------------------------------------------------------------

<AR2>

In tunnel i will reserve bw using command and using CT0.

interface Tunnel0/0/1

 shutdown

 ip address unnumbered interface LoopBack0

 tunnel-protocol mpls te

 destination 4.4.4.4

 mpls te tunnel-id 2

 mpls te priority 0

 mpls te bandwidth ct0 1000

 mpls te commit

 mpls

#

later you can see reserved bw in display for setup pri 0 and CT0.

  Link ID:  GigabitEthernet0/0/2

  Bandwidth Constraint Model   :  RDM

  Maximum Link Reservable Bandwidth(Kbits/sec):  100000

  Reservable Bandwidth BC0(Kbits/sec)         :  100000 

  Reservable Bandwidth BC1(Kbits/sec)         :  10000 

  Downstream Bandwidth (Kbits/sec)           :  1000

  IPUpdown Link Status                       :  UP

  PhysicalUpdown Link Status                 :  UP

  GracefulUpdown Link Status                 :  DOWN

  ----------------------------------------------------------------------

  TE-CLASS  CT    PRIORITY   BW RESERVED   BW AVAILABLE   DOWNSTREAM

                             (Kbit/sec)     (Kbit/sec) RSVPLSPNODE COUNT

  ----------------------------------------------------------------------

     0      0        0           1000          99000            1

     1      0        1           0             99000            0

     2      0        2           0             99000            0

     3      0        3           0             99000            0

     4      0        4           0             99000            0

     5      0        5           0             99000            0

     6      0        6           0             99000            0

     7      0        7           0             99000            0

     8      1        0           0             10000            0

     9      1        1           0             10000            0

     10     1        2           0             10000            0

     11     1        3           0             10000            0

     12     1        4           0             10000            0

     13     1        5           0             10000            0

     14     1        6           0             10000            0

     15     1        7           0             10000            0

  ----------------------------------------------------------------------

<AR2>