[j-nsp] Command to modify ADSPEC object default on PATH messages.

[Thiago Drechsel]

Hi Nalkhande.

Thanks for your help.

MTU information goes inside the PATH message, on object ADSPEC ->
"Default General Parameters" data fragment.

What I need is the command to include in the PATH Message the following
object:

ADSPEC -> "Guaranteed Service" data fragment (described on RFC2210, item
3.3.3)


Best regards.

-  
Thiago Drechsel


On Fri, 2009-08-07 at 20:30 +0530, Nalkhande Tarique Abbas wrote:
> AFAIK, JUNOS uses the Adspec field for maximum transmission unit (MTU)
> negotiation.
> 
> So when an LSP is created across a set of links with different MTU
> sizes, the ingress router does not know what the smallest MTU is on the
> LSP path. By default, the maximum packet size for the LSP is based on
> the MTU for the outgoing interface for the LSP on the ingress router.
> 
> If this MTU is larger than the MTU of one of the intermediate links,
> traffic might be dropped, because MPLS packets cannot be fragmented. 
> 
> To prevent this type of packet loss in MPLS LSPs, you can configure MTU
> signaling in RSVP. Juniper supports the Integrated Services object for
> MTU signaling in RSVP. 
> 
> MTU signaling in RSVP is disabled by default.
> To configure maximum transmission unit (MTU) signaling in RSVP, you need
> to configure MPLS to allow IP packets to be fragmented before they are
> encapsulated in MPLS. You also need to configure MTU signaling in RSVP. 
> To configure MTU signaling in RSVP, include the path-mtu statement:
> 
> path-mtu { 
> allow-fragmentation; 
> rsvp { 
> mtu-signaling;  <<--
> } 
> }
> 
> lab at ntarique# run show mpls lsp transit detail 
> Transit LSP: 1 sessions
> 
> 192.168.255.1
>   From: 192.168.255.7, LSPstate: Up, ActiveRoute: 1
> 
> ... truncated...
> 
>   FastReroute desired
>   PATH rcvfrom: 192.168.245.46 (so-0/2/1.0) 42 pkts
>   Adspec: received MTU 1500 sent MTU 1500  <<<---
>  
> 
> 
> Thanks & Regards,
> Tarique A. Nalkhande
> 
> -----Original Message-----
> From: juniper-nsp-bounces at puck.nether.net
> [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Thiago
> Drechsel
> Sent: Friday, August 07, 2009 6:37 PM
> To: Juniper List
> Subject: [j-nsp] Command to modify ADSPEC object default on PATH
> messages.
> 
> Hi list.
> 
> Does anybody know what is the configuration needed to add "Guaranteed
> Service" parameters, on ADSPEC object (RSVP PATH messages)?
> 
> By default, I see that JUNOS only sends "Default General Parameters" and
> "Controlled Load" within PATH....
> 
> Thank you!
>