Server Trail Usage and Behavior

[richard.carter]

I am looking for detailed documentation of Server Trails in the ONS15454 at Rel 7.0.

[a-vazquez]

Release 7.0. it is called Server Trail. Before going there, I would like to understand your rationale for going that route. Have you experienced any DCC congestion symptoms? I would normally recommend server trails only when necessary, ie large networks with hundreds of nodes. There are a lot of other (better) options before going to server trails.

[richard.carter]

In my architecture I have a long haul sonet provider between two of my 454 nodes. The reason that I am trying to use server trail(s) is that the sonet provider is not supporting DCC pass through nor tunneling. I am trying to implement a server trail because it looks like it would support my desire to use the CTC for end to end provisioning without having to build a circuit in two seperate pieces.

Is this an incorrect application for a server trail ?

Also, a question that is not clear from the documentation:

Does a server trail create a DCC communications pathway for DCC information within the payload of the DS-3 or OC-x or does it just create a logical link on the CTC display ?

RPC

[khollasc]

Its a logical link - end-to-end IP connectivity is still required.

[b.ransom]

Server tails is the only way we were able to deploy ONS15310 accross third party Mux's and manage via CTC. Our privisoning was 3- STS's accross a "non chanelized" OC3- In other words in this case we had to make sure the OC3 was non-concatitated STS-1's. Some running around time with the Telco to make sure his equip. was set bi-directional, revertive and so-forth. It does work so far.

Good luck

[gbarone]

A server trail is a non-DCC link across a third-party network that connects two CTC network domains.

It will allow A-Z routing even across non-CTC networks in Mariner (7.0).

Based on ITU-T G.805 : Architecture of Transport Networks.

In Future : To connect 153xx edge CTPs.

Available for both SDH and SONET clouds, but not mixed.

Server Trails can take any circuit size (sts1, vt1.5, sts3c ..).

The end ports of a server trail can be of different types (OC12 port to OC3 port, etc.).

- Server trails is a logical mapping between specific timeslots on OC/STM cards installed in different NEs without direct DCC connectivity.

- It is used to easily create circuts between nodes that are not directly connected via DCC or link traversing 3rd party network.

- Server trails do not create any circuit by itself. Once you have configured a Server trail between two NE, you will then be able to use A-Z provisioning to create circuits (same sizes of your server trail).

- No signaling is actually exchanged by terminating NEs to allow any sort of out of band transport of Overhead Bytes.

- Only UPSR or SNCP protection is available on Server trails.

No possibility to create BLSR or MS-SPR rings, this is prevented by SW; You need to have DCC enabled in order to configure BLSR or MS-SPR on a specific STM or OC card.

- No possibility to have PCA ( Protection Channel Access) over Server Trails. PCA is available only for BLSR or MS-SPR rings.

- UNPROTECTED, FULLY PROTECTED, PREEMPTIBLE are weighting flags used for path determination when a circuit is created.

If you have two leased line protecting one to each other, you need to create two UNPROTECTED Server trails, one for each line.

If you create a PROTECTED Server trail, CTC assume that the circuits going out from that specific port will be protected by Provider network and will not look for a secondary path from source to destination.

-You can create multiple server trails from the same port.

The maximum number is determined by how many circuits of a particular server trail size can be supported on the port.

A Server Trail link will only route circuits of the same size as the connection size of the ServerTrail.

- No specific documentation on Server is available for end customer a part from information included in ONS15454 reference manual and procedure guides:

http://www.cisco.com/en/US/products/hw/optical/ps2006/products_technical_reference_chapter09186a00804f8dea.html#wp126242

http://www.cisco.com/en/US/products/hw/optical/ps2006/products_installation_and_configuration_guide_chapter09186a00804f8da1.html#wp671133